Currently QtSetup.cmake checks if there's a ".git" dir and defaults to CMAKE_BUILD_TYPE=Debug in such a case.
That's kinda weird considering it somewhat overlaps with FEATURE_developer_build.
We should probably remove the .git check, and just default to Release.
Explicitly opting into FEATURE_developer_build should set it to Debug.
This may or may not have some consequences in the CI, per-repo builds, and standalone tests builds.
So care should be taken to check all those cases.