cygwin: fix python versions again
cygwin: fix python versions again

Now cygwin seems to have completed a migration of the default python to
3.9, so that is where the devel package is at.

Back out the changes from commit 3304a38496a52052ae9d58ed2459c7deb18ca703
and update the pip/wheel packages as appropriate.

pexip/meson,pexip/meson,mesonbuild/meson,mesonbuild/meson,mesonbuild/meson,mesonbuild/meson,mesonbuild/meson,mesonbuild/meson,mesonbuild/meson,pexip/meson,pexip/meson,pexip/meson,pexip/meson,mesonbuild/meson,pexip/meson,mesonbuild/meson,mesonbuild/meson,pexip/meson,pexip/meson,pexip/meson