## Issue Addressed
Resolves#1512
## Proposed Changes
- Adds a new docker Github Actions workflow
- Removes the Dockerhub hook
- Adds a new Dockerfile for use with pre-existing cross-compiled binaries
- on pushes to `unstable`
- builds an ARM64 image and tags it `latest-arm64-unstable`
- builds an AMD64 image and tags it `latest-amd64-unstable`
- builds an multiarch image by creating a manifest list referencing the prior two images and tags it `latest-unstable`
- on pushes to `stable`
- builds an ARM64 image and tags it `latest-arm64`
- builds an AMD64 image and tags it `latest-amd64`
- builds an multiarch image by creating a manifest list referencing the prior two images and tags it `latest`
## Additional Info
- for ARM64, first `cross` is used to cross compile the `lighthouse` and `lcli` binaries, then `docker buildx` is installed to actually build the docker image for the correct target platform. The image build pretty much just copies the binaries from local into the docker image (thanks @michaelsproul :) )
- The AMD64 and ARM64 builds run in parallel, in total it's been taking around 45mins on a local runner
- This PR does **not** cover version tags on docker images at the moment
Co-authored-by: realbigsean <seananderson33@gmail.com>
