ruff

ecf00cdf - Fix incorrect doc in `shebang-not-executable (EXE001)` and add git+windows solution to executable bit (#15208)

Fix incorrect doc in `shebang-not-executable (EXE001)` and add git+windows solution to executable bit (#15208) ## Summary I noticed that the solution mentioned in [shebang-not-executable (EXE001)](https://docs.astral.sh/ruff/rules/shebang-not-executable/#shebang-not-executable-exe001) was incorrect and likely copy-pasted from [shebang-missing-executable-file (EXE002)](https://docs.astral.sh/ruff/rules/shebang-missing-executable-file/#shebang-missing-executable-file-exe002) It was telling users to remove the executable bit from a non-executable file. Which does nothing. I also noticed locally that: - `chmod` wouldn't cause any file change to be noticed by git (`EXE` was also passing locally) under WSL - Using git allows anyone to fix this lint across OSes, for projects with CIs using git So I added a solution using [git update-index --chmod](https://git-scm.com/docs/git-update-index#Documentation/git-update-index.txt---chmod-x) ## Test Plan No test plan, doc changes only. As for running the chmod commands: https://github.com/python/typeshed/pull/13346