[`flake8-type-checking`] Fix some safe fixes being labeled unsafe (#15638)
## Summary
We were mistakenly using `CommentRanges::has_comments` to determine
whether our edits
were safe, which sometimes expands the checked range to the end of a
line. But in order to
determine safety we need to check exactly the range we're replacing.
This bug affected the rules `runtime-cast-value` (`TC006`) and
`quoted-type-alias` (`TC008`)
although it was very unlikely to be hit for `TC006` and for `TC008` we
never hit it because we
were checking the wrong expression.
## Test Plan
`cargo nextest run`