Update the python version for python-lxml and python-ply packages.
'dblate' now depends on python39, so that will be installed and made the
default by alternatives, so make sure that these python packages are
also available for that python version.
Install autoconf and automake, and run winsup/autogen.sh, and don't have
it silently ignore failures.
On AppVeyor:
- use latest VM image, to reduce time spent installing updates.
- run the testsuite, but ignore the result, as some tests don't work
correctly.
- hardcode the python-lxml and python-ply packages to install, so we get
ones for the right python.
- install texlive collections now needed to build documentation.
On github:
- Use a copr for cocom, since RPMSphere's package updates don't track
fedora:latest very efficently.