[`perflint`] Fix comment duplication in fixes (`PERF401`, `PERF403`) (#23729)
## Summary
- Fix comments inside if test and for target being duplicated when
transforming a for-loop into a comprehension
## Test Plan
- Added test cases for both PERF401 and PERF403
- Verified comments appear exactly once in preview snapshot fixes
## Closes: [#18787](https://github.com/astral-sh/ruff/issues/18787)
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