Dropping the mingw-w64-toolchain requirement for makepkg-mingw and building in CI

[lazka]

I've recently tried to get rid of not explicitly defined dependencies by cleaning up base-devel and adding them to makedepends in all packages instead, to make base-devel smaller and to make the real dependency tree visible to our automation.

Similarly we have those mingw-w64-XXX-toolchain groups which we require to be installed when running makepkg-mingw where many packages skip to define their makedepends if they happen to be pulled in by those groups.

A simple package requiring a C compiler will then pull in 151.34 MiB of packages instead of the 46.85 MiB it really needs for building.

Not needing those groups would:

• make CI faster
• help autobuild figure out how to rebuild things without assuming everything depends on the toolchain
• require users to install one thing less before they can start building packages

Thus I propose to remove the requirement for mingw-w64-XXX-toolchain groups to be installed when running makepkg-mingw (the groups will stay as is):

• Make all packages makedepend on things they need that are currently provided by the groups
  • Make packages depend on a C compiler -> 7c67d9c
  • What about pkg-config? -> 0dfda3f
  • Anything else ? -> We'll see in CI
• Switch CI to only install cc -> 0ca9cf2
• Remove the warning about the toolchain missing in makepkg-mingw -> pacman: no longer require toolchains to be installed when running makepkg-mingw MSYS2-packages#2799
• Update the documentation accordingly -> msys2/msys2.github.io@231b3f8
• Don't install anything in CI besides base-devel -> c2c5009
• Don't install the groups in autobuild -> msys2/msys2-autobuild@6a436ac

[revelator]

i was wondering if the addition of ${MINGW_PACKAGE_PREFIX}-cc had anything to do with these changes ? since it forces a rebuild of the compiler without other changes.

[lazka]

yes, so packages can easily depend on a C compiler. Previously we had clang in clang32/64 provide a virtual "gcc" package, but that confused people and they removed it every time.

[revelator]

ah ok i was starting to wonder :)

[lazka]

This is all done now.