Run wheel building tests on a PR

CI configuration and testing

Pull requests that update a dependency file

https://matplotlib.org/devdocs/devel/contribute.html#good-first-issues

https://matplotlib.org/devdocs/devel/contribute.html#good-first-issues

https://matplotlib.org/devdocs/devel/contribute.html#good-first-issues

Last-resort; prefer specific mechanisms if possible: draft PR, request changes, specific labels

files in lib/ and doc/api

files in galleries/examples

files in galleries/plot_types

tagging examples + proposing new tags