[Feature-Request] - Add auto publishing to DockerHub/GHCR on release

[YOU54F]

See pact-foundation/pact-reference#446

Related epic: pact-foundation/roadmap#29

[YOU54F]

Scripts updated to publish to ghcr as well.

https://github.com/pact-foundation/pact-core-mock-server/pkgs/container/pact-mock-server

note the rename to drop -ref- from the name, so pact-ref-mock-server is now pact-mock-server

Just need to have a PAT with write:packages access, and login to the ghcr.io registry with

docker login ghcr.io

enter username and pat code.

run ./release-docker.sh VERSION as usual

job jobbed.

We could add it at the end of the release, similar to pact-stub-server

https://github.com/pact-foundation/pact-stub-server/blob/03dce47ab2ca731609f6e4a7a31c3cfc2e03b0e8/.github/workflows/release.yml#L77