Run rustfmt on nightly to clean up erroneous comments (#5106)

## Summary

This PR runs `rustfmt` with a few nightly options as a one-time fix to
catch some malformatted comments. I ended up just running with:

```toml
condense_wildcard_suffixes = true
edition = "2021"
max_width = 100
normalize_comments = true
normalize_doc_attributes = true
reorder_impl_items = true
unstable_features = true
use_field_init_shorthand = true
```

Since these all seem like reasonable things to fix, so may as well while
I'm here.

crates/ruff_python_formatter/src/comments/placement.rs

@@ -656,7 +656,7 @@ fn handle_positional_only_arguments_separator_comment<'a>(
 /// Handles comments between the left side and the operator of a binary expression (trailing comments of the left),
 /// and trailing end-of-line comments that are on the same line as the operator.
 ///
-///```python
+/// ```python
 /// a = (
 ///     5 # trailing left comment
 ///     + # trailing operator comment

crates/ruff_python_formatter/src/comments/visitor.rs

@@ -257,6 +257,7 @@ impl<'ast> PreorderVisitor<'ast> for CommentsVisitor<'ast> {
 
         self.finish_node(withitem);
     }
+
     fn visit_match_case(&mut self, match_case: &'ast MatchCase) {
         if self.start_node(match_case).is_traverse() {
             walk_match_case(self, match_case);