fix: remove trailing spaces when rewriting same line missing comments

[ytmimi]

Fixes #6568

When using style_edition=2024 trailing whitespace was not properly removed when foramtting same line comments.

[calebcartwright]

i think we may need to gate this behind 27, as annoying as that would be.

thoughts?

[ytmimi]

The thought crossed my mind. though I think the caveats in our stability guarantee cover us here. I think either the note about comments or bugs would apply.

To quote what we have in the README (emphasis mine):

The following list enumerates areas where Rustfmt does not work or where the stability guarantees do not apply (we don't make a distinction between the two because in the future Rustfmt might work on code where it currently does not):

• a program where any part of the program does not parse (parsing is an early stage of compilation and in Rust includes macro expansion).
• Macro declarations and uses (current status: some macro declarations and uses are formatted).
• Comments, including any AST node with a comment 'inside' (Rustfmt does not currently attempt to format comments, it > does format code with comments inside, but that formatting may change in the future).
• Rust code in code blocks in comments.
• Any fragment of a program (i.e., stability guarantees only apply to whole programs, even where fragments of a program can be formatted today).
• Code containing non-ascii unicode characters (we believe Rustfmt mostly works here, but do not have the test coverage or experience to be 100% sure).
• Bugs in Rustfmt (like any software, Rustfmt has bugs, we do not consider bug fixes to break our stability guarantees).