Add a GitHub action based release job

[ericwill]

Signed-off-by: Eric Williams ericwill@redhat.com

What does this PR do?

Adds a GitHub action based release job system to the devfile registry.

Screenshot/screencast of this PR

N/A

What issues does this PR fix or reference?

Part of eclipse-che/che#18072

How to test this PR?

Modify the VERSION file on the release branch and push the changes.

PR Checklist

As the author of this Pull Request I made sure that:

• The Eclipse Contributor Agreement is valid
• Code produced is complete
• Code builds without errors
• Tests are covering the bugfix
• The repository devfile is up to date and works
• Sections What issues does this PR fix or reference and How to test this PR completed
• Relevant user documentation updated
• Relevant contributing documentation updated
• CI/CD changes implemented, documented and communicated

Reviewers

Reviewers, please comment how you tested the PR when approving it.

[ericwill]

About the secrets, you can add the secret via GitHub API like so: https://developer.github.com/v3/actions/secrets/#create-or-update-a-repository-secret

There is an automated way to do it (thanks to @benoitf), just make sure you change the generate.sh script to set DOCKERHUB_USERNAME and DOCKERHUB_PASSWORD instead of the QUAY_* ones.

[nickboldt]

As I'm not privy to the values of these secrets, and can't copy them from another eclipse/che-* repo (I'm not an admin)... I'll ask that someone like @benoitf runs his script and pushes the secrets to this and teh che-plugin-registry repo too.

If feeling particularly bored, could repeat the same steps for all the other repos that need to be migrated to GH action from centos ci: eclipse-che/che#17857