Pushes to main run the tests. The Deploy button publishes the Windows, RPM,
deb and F-Droid packages to the same NAS directories a dev machine uses, with
the same keys, then runs update-repo.sh, so public URLs don't change.
Builds run on Debian 12, in an image defined in ci/builder, so the Linux
packages now need glibc 2.36 instead of Fedora 44's 2.43.
scripts/windows-publish.sh builds the NSIS setup.exe for
x86_64-pc-windows-msvc through cargo-xwin, versioned like the RPM and
APK, and copies it into a folder to serve: the newest three installers,
a stable mtgc-latest-x64-setup.exe, and SHA256SUMS.
