A new image tag for the runner stopped being published on master merges from changes in #86.
This fixes that in the following ways:
- Tests the GH workflow on PRs w/o pushing the images
- Runner and Docker version are moved from Makefile to GH Actions workflow and are passed in as build args
- GHA workflow runs on PRs, and if the workflow file itself is changed (i.e. version bump) or the runner Docker source changes (excluding the Makefile since thats just for local dev)
- Images are pushed on push (i.e. a merge)
Adding multi-arch image support for `arm64` and `amd64`. This uses dockers new `buildx` feature, to enable further architectures more work will be required to update the `runner/Dockerfile` file to pull architecture-specific releases.
The Makefile targets really should only be used for local testing and not for release, additional work to appropriately tag the release images may need to be added but for now, I've not added that logic.
Fixes: #86
Signed-off-by: Michael Fornaro <20387402+xUnholy@users.noreply.github.com>
