pre-commit markdown-it-py<3 (for Python 3.7 compatibility) (#4704)

* markdown-it-py dropped Python 3.7 support, but we are type checking for Python 3.7 from a newer version of Python. Keep using markdown-it-py<3 as long as we support Python 3.7.

* Shuffle order of pre-commit checks for better agility.
1 file changed