[MSYS2] not detected in ofMenu #8640

When running ofMenu in a MSYS2 UCRT64, the system is detected as vs / 64.
As a consequence, when setup is launch, the vs liraries are downloaded.

I agree that "vs" should be set if of.sh is run from Git bash .
However, in a UCRT64 (or CLANG64 or CLANGARM64) MSYS2 shell, we should detect a msys2 environment.

Solution proposal

Git Bash has git-bash.exe in / which is not present in MSYS2 environment.
If it is present, use "vs"; if not, use "msys2".