Revert "TYP: Many typing constructs are invariant"
I accidentally pushed to pandas instead of my fork :(

Is it possible in github to disallow direct pushes to the repository (only allow PRs)?

edit: It seems that this is possible https://stackoverflow.com/a/57685576
@jreback @simonjayhawkins  go ahead and merge when ready

i think can prevent merging directly to master I protected the main branch from direct pushes. Some windows tests fail with:

> ImportError: the 'read_file' function requires the 'fiona' package, but it is not installed or does not import correctly.
> Importing fiona resulted in: DLL load failed while importing ogrext: The specified procedure could not be found.

Seems unrelated, but I am not going to merge this myself - messed up enough for today :( yep yep totally fine @twoertwein  > I protected the main branch from direct pushes.

@jreback the release scripts do a direct push. for main this is only an issue for rc. Is 1.4.x protected? nope other branches are not protected 