Support for macOS Catalina 10.15?

https://www.apple.com/macos/catalina/

https://github.com/actions/virtual-environments/issues/53

In GitHub Actions, runs-on: macOS-10.14 works as expected but runs-on: macOS-10.15 does not.

That would make sense since 10.15 is not officially supported (yet). Just 10.14 is available for now.

According to this PR from GitHub staff, it’s already planned.