RUF031 fix introduces a syntax error when the tuple contains a slice

[dscorbett]

The fix for RUF031 introduces a syntax error when lint.ruff.parenthesize-tuple-in-subscript = true and the subscripted tuple contains a slice.

$ ruff --version
ruff 0.5.7
$ cat ruf031.py
x[:,]
$ ruff check --isolated --preview --select RUF031 --config 'lint.ruff.parenthesize-tuple-in-subscript = true' ruf031.py --fix

error: Fix introduced a syntax error. Reverting all changes.

This indicates a bug in Ruff. If you could open an issue at:

    https://github.com/astral-sh/ruff/issues/new?title=%5BFix%20error%5D

...quoting the contents of `ruf031.py`, the rule codes RUF031, along with the `pyproject.toml` settings and executed command, we'd be very appreciative!

ruf031.py:1:3: RUF031 Use parentheses for tuples in subscripts.
  |
1 | x[:,]
  |   ^^ RUF031
  |
  = help: Parenthesize the tuple.

Found 1 error.
[*] 1 fixable with the `--fix` option.

[dylwil3]

Thanks! I'll take a stab at this.