clang: build mingw env with gcc again
clang: build mingw env with gcc again

there are some issues, so leave that for later:
https://github.com/msys2/MINGW-packages/pull/12550#issuecomment-1219768532

Not increasing pkgrel to avoid clang env rebuilds, I'll clear staging
manually.

stahta01/MINGW-packages,stahta01/MINGW-packages,lhmouse/MINGW-packages,oscarfv/MINGW-packages,JPeterMugaas/MINGW-packages,stahta01/MINGW-packages,oscarfv/MINGW-packages,lhmouse/MINGW-packages,lhmouse/MINGW-packages,stahta01/MINGW-packages,oscarfv/MINGW-packages,oscarfv/MINGW-packages,lhmouse/MINGW-packages,lhmouse/MINGW-packages,JPeterMugaas/MINGW-packages,oscarfv/MINGW-packages,JPeterMugaas/MINGW-packages,stahta01/MINGW-packages,JPeterMugaas/MINGW-packages,oscarfv/MINGW-packages,lhmouse/MINGW-packages,JPeterMugaas/MINGW-packages,JPeterMugaas/MINGW-packages,stahta01/MINGW-packages