Control: tags -1 -patchUpstream will fix this probably soon by merging https://github.com/astropy/astropy/pull/13614 into their development branch and backporting it to the 5.1 version. Probably then they will issue a bugfix version, as the PR covers all fixes for the upcoming Python 3.11.
I will wait for this bugfix version, as Python 3.11 will also soon knock on the Debian's door, and we need this anyway.
