On old macOS bots we only want to provision Mono, so change the logic so that
we first ignore everything, then re-enable Mono.
This way we don't have to add new ignore flags here every time we add
something new to the provisioning script.
This fixes an issue where the script detects that dotnet isn't installed, and
shows an error, when trying to run tests on older macOS bots in CI.
brew may fail to install 7z if 7z is already installed, so ignore any brew
failures when trying to install 7z.
If 7z really is non-functional on the machine, then it'll fail later anyway.
Fixes this warning:
make: *** tools/siminstaller: No such file or directory. Stop.
Can't check if simulators are available, because siminstaller failed to build.
Fix retry-download-on-error-56 logic to not fail forever if the first time
failed by resetting the EC variable after each try.
Fixes https://github.com/xamarin/maccore/issues/1098 (third time's the charm!)
Rolf Bjarne Kvinge