CLN: 29547 replace .format() with f-strings
This PR replaces .format() with f-strings as requested in https://github.com/pandas-dev/pandas/issues/29547.

It did this replacement in scripts/find_commits_touching_func.py

- [x] tests added / passed
- [x] passes `black pandas`
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`

I was checking, and seems like this script is not working, and I don't think anyone is using it. I'm removing it in #32071, so better to close this PR. Thanks for the work anyway, and sorry for not detecting that earlier.