Github action for release
for initial feedback. maybe way off base with this.

can be seen in action at https://github.com/simonjayhawkins/pandas/actions

the alternative of retaining a separate repo for release can be seen at https://github.com/simonjayhawkins/pandas-release/actions
closing. wanted to avoid sharing credentials between repos just for tagging but going to continue using pandas-release for a bit. I've re-opened so we have somewhere to discuss implementation details.

This is based off a workflow that I am using to test release readiness for the backport branch that I run manually.

I think, since the backport branch doesn't have too many commits, could change this from a manual trigger to run on push to 1.1.x @simonjayhawkins move to pandas-release repo? > @simonjayhawkins move to pandas-release repo?

probably need more discussion in #21050 before we can make progress here. closing to clear queue.