[red-knot] Detect version-related syntax errors (#16379)

## Summary
This PR extends version-related syntax error detection to red-knot. The
main changes here are:

1. Passing `ParseOptions` specifying a `PythonVersion` to parser calls
2. Adding a `python_version` method to the `Db` trait to make this
possible
3. Converting `UnsupportedSyntaxError`s to `Diagnostic`s
4. Updating existing mdtests  to avoid unrelated syntax errors

My initial draft of (1) and (2) in #16090 instead tried passing a
`PythonVersion` down to every parser call, but @MichaReiser suggested
the `Db` approach instead
[here](https://github.com/astral-sh/ruff/pull/16090#discussion_r1969198407),
and I think it turned out much nicer.

All of the new `python_version` methods look like this:

```rust
fn python_version(&self) -> ruff_python_ast::PythonVersion {
    Program::get(self).python_version(self)
}
```

with the exception of the `TestDb` in `ruff_db`, which hard-codes
`PythonVersion::latest()`.

## Test Plan

Existing mdtests, plus a new mdtest to see at least one of the new
diagnostics.

crates/red_knot_test/src/assertion.rs

@@ -489,13 +489,27 @@ pub(crate) enum ErrorAssertionParseError<'a> {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use red_knot_python_semantic::{Program, ProgramSettings, PythonPlatform, SearchPathSettings};
     use ruff_db::files::system_path_to_file;
     use ruff_db::system::DbWithWritableSystem as _;
+    use ruff_python_ast::PythonVersion;
     use ruff_python_trivia::textwrap::dedent;
     use ruff_source_file::OneIndexed;
 
     fn get_assertions(source: &str) -> InlineFileAssertions {
         let mut db = Db::setup();
+
+        let settings = ProgramSettings {
+            python_version: PythonVersion::default(),
+            python_platform: PythonPlatform::default(),
+            search_paths: SearchPathSettings::new(Vec::new()),
+        };
+        match Program::try_get(&db) {
+            Some(program) => program.update_from_settings(&mut db, settings),
+            None => Program::from_settings(&db, settings).map(|_| ()),
+        }
+        .expect("Failed to update Program settings in TestDb");
+
         db.write_file("/src/test.py", source).unwrap();
         let file = system_path_to_file(&db, "/src/test.py").unwrap();
         InlineFileAssertions::from_file(&db, file)