GitHub Actions' macOS runners have Python from homebrew installed and it's used by default instead of the Python that ships with macOS. Apparently Homebrew decided you shouldn't be able to install stuff with `pip3` anymore so our build broke since `setuptools` is no longer included by default and `glib` from vcpkg needs it to build.
Additionally,, the whole liblzma mess ended up breaking our builds too because libarchive (and its dependency libxml2) depends on it and the download is no longer available. The build option changes here should be reverted once this is sorted out because this is probably partially breaking archive support.
PS: Fuck you Jia Tan.
* Integrate support for building with dependencies from vcpkg
Configure the build using -DUSE_VCPKG=ON to use vcpkg. By default
recommended triplets targeting the OS versions official builds support
are used. You can opt out of this with -DUSE_RECOMMENDED_TRIPLETS=OFF.
* Add the vcpkg manifest
* Fetch vcpkg with FetchContent if we don't have it
* macOS cross compiling fixes
- can't use the x86_64 one as host triplet on arm64 because building Qt
fails for whatever reason. Because of course it does :D
- vcpkg doesn't always like periods in triplet names so removed those
* x86_64 macOS should also use its recommended target when building arm64 builds
