New pycodestyle.max-line-length option (#8039)

## Summary

This PR introduces a new `pycodestyl.max-line-length` option that allows overriding the global `line-length` option for `E501` only.

This is useful when using the formatter and `E501` together, where the formatter uses a lower limit and `E501` is only used to catch extra-long lines. 

Closes #7644

## Considerations

~~Our fix infrastructure asserts in some places that the fix doesn't exceed the configured `line-width`. With this change, the question is whether it should use the `pycodestyle.max-line-width` or `line-width` option to make that decision.
I opted for the global `line-width` for now, considering that it should be the lower limit. However, this constraint isn't enforced and users not using the formatter may only specify `pycodestyle.max-line-width` because they're unaware of the global option (and it solves their need).~~


~~I'm interested to hear your thoughts on whether we should use `pycodestyle.max-line-width` or `line-width` to decide on whether to emit a fix or not.~~

Edit: The linter users `pycodestyle.max-line-width`. The `line-width` option has been removed from the `LinterSettings`

## Test Plan

Added integration test. Built the documentation and verified that the links are correct.

crates/ruff_workspace/src/configuration.rs

@@ -21,6 +21,7 @@ use ruff_linter::line_width::{LineLength, TabSize};
 use ruff_linter::registry::RuleNamespace;
 use ruff_linter::registry::{Rule, RuleSet, INCOMPATIBLE_CODES};
 use ruff_linter::rule_selector::{PreviewOptions, Specificity};
+use ruff_linter::rules::pycodestyle;
 use ruff_linter::settings::rule_table::RuleTable;
 use ruff_linter::settings::types::{
     FilePattern, FilePatternSet, PerFileIgnore, PreviewMode, PythonVersion, SerializationFormat,
@@ -183,6 +184,8 @@ impl Configuration {
         let lint = self.lint;
         let lint_preview = lint.preview.unwrap_or(global_preview);
 
+        let line_length = self.line_length.unwrap_or_default();
+
         Ok(Settings {
             cache_dir: self
                 .cache_dir
@@ -225,7 +228,6 @@ impl Configuration {
                     .unwrap_or_else(|| DUMMY_VARIABLE_RGX.clone()),
                 external: FxHashSet::from_iter(lint.external.unwrap_or_default()),
                 ignore_init_module_imports: lint.ignore_init_module_imports.unwrap_or_default(),
-                line_length: self.line_length.unwrap_or_default(),
                 tab_size: self.tab_size.unwrap_or_default(),
                 namespace_packages: self.namespace_packages.unwrap_or_default(),
                 per_file_ignores: resolve_per_file_ignores(
@@ -346,10 +348,14 @@ impl Configuration {
                     .map(Pep8NamingOptions::try_into_settings)
                     .transpose()?
                     .unwrap_or_default(),
-                pycodestyle: lint
-                    .pycodestyle
-                    .map(PycodestyleOptions::into_settings)
-                    .unwrap_or_default(),
+                pycodestyle: if let Some(pycodestyle) = lint.pycodestyle {
+                    pycodestyle.into_settings(line_length)
+                } else {
+                    pycodestyle::settings::Settings {
+                        max_line_length: line_length,
+                        ..pycodestyle::settings::Settings::default()
+                    }
+                },
                 pydocstyle: lint
                     .pydocstyle
                     .map(PydocstyleOptions::into_settings)

crates/ruff_workspace/src/options.rs

@@ -60,7 +60,7 @@ pub struct Options {
     /// this base configuration file, then merge in any properties defined
     /// in the current configuration file.
     #[option(
-        default = r#"None"#,
+        default = r#"null"#,
         value_type = "str",
         example = r#"
             # Extend the `pyproject.toml` file in the parent directory.
@@ -132,7 +132,7 @@ pub struct Options {
     /// results across many environments, e.g., with a `pyproject.toml`
     /// file).
     #[option(
-        default = "None",
+        default = "null",
         value_type = "str",
         example = r#"
             required-version = "0.0.193"
@@ -362,6 +362,8 @@ pub struct Options {
     /// Note: While the formatter will attempt to format lines such that they remain
     /// within the `line-length`, it isn't a hard upper bound, and formatted lines may
     /// exceed the `line-length`.
+    ///
+    /// See [`pycodestyle.max-line-length`](#pycodestyle-max-line-length) to configure different lengths for `E501` and the formatter.
     #[option(
         default = "88",
         value_type = "int",
@@ -1043,7 +1045,7 @@ pub struct Flake8CopyrightOptions {
 
     /// Author to enforce within the copyright notice. If provided, the
     /// author must be present immediately following the copyright notice.
-    #[option(default = "None", value_type = "str", example = r#"author = "Ruff""#)]
+    #[option(default = "null", value_type = "str", example = r#"author = "Ruff""#)]
     pub author: Option<String>,
 
     /// A minimum file size (in bytes) required for a copyright notice to
@@ -2247,6 +2249,32 @@ impl Pep8NamingOptions {
 #[serde(deny_unknown_fields, rename_all = "kebab-case")]
 #[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
 pub struct PycodestyleOptions {
+    /// The maximum line length to allow for [`line-too-long`](https://docs.astral.sh/ruff/rules/line-too-long/) violations. By default,
+    /// this is set to the value of the [`line-length`](#line-length) option.
+    ///
+    /// Use this option when you want to detect extra-long lines that the formatter can't automatically split by setting
+    /// `pycodestyle.line-length` to a value larger than [`line-length`](#line-length).
+    ///
+    /// ```toml
+    /// line-length = 88 # The formatter wraps lines at a length of 88
+    ///
+    /// [pycodestyle]
+    /// max-line-length = 100 # E501 reports lines that exceed the length of 100.
+    /// ```
+    ///
+    /// The length is determined by the number of characters per line, except for lines containing East Asian characters or emojis.
+    /// For these lines, the [unicode width](https://unicode.org/reports/tr11/) of each character is added up to determine the length.
+    ///
+    /// See the [`line-too-long`](https://docs.astral.sh/ruff/rules/line-too-long/) rule for more information.
+    #[option(
+        default = "null",
+        value_type = "int",
+        example = r#"
+            max-line-length = 100
+        "#
+    )]
+    pub max_line_length: Option<LineLength>,
+
     /// The maximum line length to allow for [`doc-line-too-long`](https://docs.astral.sh/ruff/rules/doc-line-too-long/) violations within
     /// documentation (`W505`), including standalone comments. By default,
     /// this is set to null which disables reporting violations.
@@ -2256,7 +2284,7 @@ pub struct PycodestyleOptions {
     ///
     /// See the [`doc-line-too-long`](https://docs.astral.sh/ruff/rules/doc-line-too-long/) rule for more information.
     #[option(
-        default = "None",
+        default = "null",
         value_type = "int",
         example = r#"
             max-doc-length = 88
@@ -2278,9 +2306,10 @@ pub struct PycodestyleOptions {
 }
 
 impl PycodestyleOptions {
-    pub fn into_settings(self) -> pycodestyle::settings::Settings {
+    pub fn into_settings(self, global_line_length: LineLength) -> pycodestyle::settings::Settings {
         pycodestyle::settings::Settings {
             max_doc_length: self.max_doc_length,
+            max_line_length: self.max_line_length.unwrap_or(global_line_length),
             ignore_overlong_task_comments: self.ignore_overlong_task_comments.unwrap_or_default(),
         }
     }
@@ -2321,7 +2350,7 @@ pub struct PydocstyleOptions {
     /// enabling _additional_ rules on top of a convention is currently
     /// unsupported.
     #[option(
-        default = r#"None"#,
+        default = r#"null"#,
         value_type = r#""google" | "numpy" | "pep257""#,
         example = r#"
             # Use Google-style docstrings.