Fix regression on the GitHub finalize job

[pipex]

The work on PR #1046 made the finalize github release job dependent on the release_notes input. That's a regression on the correct behavior. This PR moves the PR comment and deploy message actions to a separate job that is dependent on the release notes input, and makes the release_notes job run on every PR, which allows the github finalize job to always run on merge.

This is a major change because it changes the way the release_notes input work, even though it restores the right behavior.

Change-type: major

Release notes

This release fixes a regression that prevented finalizing the GitHub release unless the release_comment input was set to true. This restores the correct behavior, however it is a major change as it is changing an interface (even if the interface was bad).

[ab77]

@pipex I think it's fine by looking at the changes; the ultimate test would be to run it against https://github.com/balena-io/environment-production or https://github.com/product-os/environment-production

[klutchell]

I'm seeing this regression impacting our dependency chains where we are depending on GitHub releases being created and picked up by Renovate.

[pipex]

@klutchell just rebased, I think we can merge and test the comments with the production PRs