STYLE/CI: implement incremental linting for asv benchmarks
Another try at #18620 

@mroeschke since it looks like you are going through the asv files one-by-one, the idea here is that when file X gets cleaned up, it can be un-excluded in the lint.sh command.

- [ ] closes #xxxx
- [ ] tests added / passed
- [ ] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [ ] whatsnew entry
