Changes

[Build] Ensure GH-workflow for MacOS runs on x86_64 image

GitHub Actions changed their 'latest' images for MacOS to use the
'aarch64' instead of the 'x86_64' architecture:
https://github.com/actions/runner-images/blob/7bb1d84f7071bfa9c350d7552d9631d9a69bfdb0/README.md

But for macosx.aarch64 no JDK-8 is available.