* Adding new workflow that builds maiko releaases for Linux/amd64, Linux/arm64, Linux/arm7, Macos/amd64. (Not Macos/arm64 as yet.) Also builds and pushes to DockerHub docker images for Linux/amd64 and Linux/arm64. Delete old buildDocker.yml workflow.
* Adding latest version of buildReleaseInclDocker.yml; builds release and docker images for all major platforms except MacOs arm64.
On pushes to master: builds images for x86_64, Apple M1, and ARMv7
architectures based on Ubuntu Focal release. This builds only the
regular lde/ldex and does NOT build the ldeinit, so these are not
suitable for doing a loadup from scratch.
Commit based on https://github.com/stumbo/maiko/tree/gitHubBuild
Homebrew on the macOS build machines for GitHub Actions was
updated to version 2.7 and that deprecated the `brew cask install`
syntax in favor of `brew install --cask`, so we need to update
here.
The announcement for the GitHub change is:
https://github.com/actions/virtual-environments/issues/2415
