Avoid missing namespace violations in scripts with shebangs (#8710)

## Summary

I think it's reasonable to avoid raising `INP001` for scripts, and
shebangs are one sufficient way to detect scripts.

Closes https://github.com/astral-sh/ruff/issues/8690.

crates/ruff_linter/src/checkers/filesystem.rs

@@ -1,6 +1,8 @@
 use std::path::Path;
 
 use ruff_diagnostics::Diagnostic;
+use ruff_python_index::Indexer;
+use ruff_source_file::Locator;
 
 use crate::registry::Rule;
 use crate::rules::flake8_no_pep420::rules::implicit_namespace_package;
@@ -10,15 +12,22 @@ use crate::settings::LinterSettings;
 pub(crate) fn check_file_path(
     path: &Path,
     package: Option<&Path>,
+    locator: &Locator,
+    indexer: &Indexer,
     settings: &LinterSettings,
 ) -> Vec<Diagnostic> {
     let mut diagnostics: Vec<Diagnostic> = vec![];
 
     // flake8-no-pep420
     if settings.rules.enabled(Rule::ImplicitNamespacePackage) {
-        if let Some(diagnostic) =
-            implicit_namespace_package(path, package, &settings.project_root, &settings.src)
-        {
+        if let Some(diagnostic) = implicit_namespace_package(
+            path,
+            package,
+            locator,
+            indexer,
+            &settings.project_root,
+            &settings.src,
+        ) {
             diagnostics.push(diagnostic);
         }
     }

crates/ruff_linter/src/checkers/tokens.rs

@@ -167,7 +167,7 @@ pub(crate) fn check_tokens(
         Rule::ShebangNotFirstLine,
         Rule::ShebangMissingPython,
     ]) {
-        flake8_executable::rules::from_tokens(tokens, path, locator, &mut diagnostics);
+        flake8_executable::rules::from_tokens(&mut diagnostics, path, locator, indexer);
     }
 
     if settings.rules.any_enabled(&[

crates/ruff_linter/src/linter.rs

@@ -117,7 +117,7 @@ pub fn check_path(
         .iter_enabled()
         .any(|rule_code| rule_code.lint_source().is_filesystem())
     {
-        diagnostics.extend(check_file_path(path, package, settings));
+        diagnostics.extend(check_file_path(path, package, locator, indexer, settings));
     }
 
     // Run the logical line-based rules.

crates/ruff_linter/src/rules/flake8_executable/rules/mod.rs

@@ -1,9 +1,7 @@
 use std::path::Path;
 
-use ruff_python_parser::lexer::LexResult;
-use ruff_python_parser::Tok;
-
 use ruff_diagnostics::Diagnostic;
+use ruff_python_index::Indexer;
 use ruff_source_file::Locator;
 pub(crate) use shebang_leading_whitespace::*;
 pub(crate) use shebang_missing_executable_file::*;
@@ -20,14 +18,14 @@ mod shebang_not_executable;
 mod shebang_not_first_line;
 
 pub(crate) fn from_tokens(
-    tokens: &[LexResult],
+    diagnostics: &mut Vec<Diagnostic>,
     path: &Path,
     locator: &Locator,
-    diagnostics: &mut Vec<Diagnostic>,
+    indexer: &Indexer,
 ) {
     let mut has_any_shebang = false;
-    for (tok, range) in tokens.iter().flatten() {
-        if let Tok::Comment(comment) = tok {
+    for range in indexer.comment_ranges() {
+        let comment = locator.slice(*range);
         if let Some(shebang) = ShebangDirective::try_extract(comment) {
             has_any_shebang = true;
 
@@ -48,7 +46,6 @@ pub(crate) fn from_tokens(
             }
         }
     }
-    }
 
     if !has_any_shebang {
         if let Some(diagnostic) = shebang_missing_executable_file(path) {

crates/ruff_linter/src/rules/flake8_no_pep420/mod.rs

@@ -16,7 +16,7 @@ mod tests {
     #[test_case(Path::new("test_pass_init"), Path::new("example.py"))]
     #[test_case(Path::new("test_fail_empty"), Path::new("example.py"))]
     #[test_case(Path::new("test_fail_nonempty"), Path::new("example.py"))]
-    #[test_case(Path::new("test_fail_shebang"), Path::new("example.py"))]
+    #[test_case(Path::new("test_pass_shebang"), Path::new("example.py"))]
     #[test_case(Path::new("test_ignored"), Path::new("example.py"))]
     #[test_case(Path::new("test_pass_namespace_package"), Path::new("example.py"))]
     #[test_case(Path::new("test_pass_pyi"), Path::new("example.pyi"))]

crates/ruff_linter/src/rules/flake8_no_pep420/rules/implicit_namespace_package.rs

@@ -1,10 +1,12 @@
 use std::path::{Path, PathBuf};
 
-use ruff_text_size::TextRange;
-
 use ruff_diagnostics::{Diagnostic, Violation};
 use ruff_macros::{derive_message_formats, violation};
+use ruff_python_index::Indexer;
+use ruff_source_file::Locator;
+use ruff_text_size::{TextRange, TextSize};
 
+use crate::comments::shebang::ShebangDirective;
 use crate::fs;
 
 /// ## What it does
@@ -42,6 +44,8 @@ impl Violation for ImplicitNamespacePackage {
 pub(crate) fn implicit_namespace_package(
     path: &Path,
     package: Option<&Path>,
+    locator: &Locator,
+    indexer: &Indexer,
     project_root: &Path,
     src: &[PathBuf],
 ) -> Option<Diagnostic> {
@@ -56,6 +60,11 @@ pub(crate) fn implicit_namespace_package(
         && !path
             .parent()
             .is_some_and( |parent| src.iter().any(|src| src == parent))
+        // Ignore files that contain a shebang.
+        && !indexer
+            .comment_ranges()
+            .first().filter(|range| range.start() == TextSize::from(0))
+            .is_some_and(|range| ShebangDirective::try_extract(locator.slice(*range)).is_some())
     {
         #[cfg(all(test, windows))]
         let path = path

crates/ruff_linter/src/rules/flake8_no_pep420/snapshots/ruff_linter__rules__flake8_no_pep420__tests__test_fail_shebang.snap

@@ -1,11 +0,0 @@
----
-source: crates/ruff_linter/src/rules/flake8_no_pep420/mod.rs
----
-example.py:1:1: INP001 File `./resources/test/fixtures/flake8_no_pep420/test_fail_shebang/example.py` is part of an implicit namespace package. Add an `__init__.py`.
-  |
-1 | #!/bin/env/python
-  |  INP001
-2 | print('hi')
-  |
-
-

crates/ruff_linter/src/rules/flake8_no_pep420/snapshots/ruff_linter__rules__flake8_no_pep420__tests__test_pass_shebang.snap

@@ -0,0 +1,4 @@
+---
+source: crates/ruff_linter/src/rules/flake8_no_pep420/mod.rs
+---
+