CI: Test NumPy main branch also with Python 3.11 (#16206)
CI: Test NumPy main branch also with Python 3.11 (#16206)

Use Python 3.11-dev in the CI job that also tests the NumPy main branch.

Python 3.11 is now in beta and feature stable. By adding a Python 3.11 test run we can
catch errors and bugs before Python 3.11 will become stable, and  packages dependent
on SciPy can start working on their Python 3.11 support.

[ci skip]
WarrenWeckesser/scipy,WarrenWeckesser/scipy,rgommers/scipy,anntzer/scipy,ilayn/scipy,endolith/scipy,andyfaff/scipy,andyfaff/scipy,scipy/scipy,Stefan-Endres/scipy,endolith/scipy,scipy/scipy,Stefan-Endres/scipy,WarrenWeckesser/scipy,andyfaff/scipy,perimosocordiae/scipy,scipy/scipy,mdhaber/scipy,endolith/scipy,ilayn/scipy,mdhaber/scipy,perimosocordiae/scipy,mdhaber/scipy,ilayn/scipy,rgommers/scipy,endolith/scipy,Stefan-Endres/scipy,andyfaff/scipy,Stefan-Endres/scipy,WarrenWeckesser/scipy,mdhaber/scipy,ilayn/scipy,andyfaff/scipy,Stefan-Endres/scipy,mdhaber/scipy,anntzer/scipy,perimosocordiae/scipy,WarrenWeckesser/scipy,mdhaber/scipy,Stefan-Endres/scipy,scipy/scipy,endolith/scipy,perimosocordiae/scipy,endolith/scipy,anntzer/scipy,perimosocordiae/scipy,ilayn/scipy,andyfaff/scipy,rgommers/scipy,anntzer/scipy,ilayn/scipy,scipy/scipy,perimosocordiae/scipy,anntzer/scipy,rgommers/scipy,WarrenWeckesser/scipy,rgommers/scipy,anntzer/scipy,scipy/scipy