Build the release Docker image on Github

[bschmalhofer]

Building of the devel Docker images seems to work. The next step is to also build the release images. This could be done in a separate workflow. Code duplication can maybe avoided by using reusable workflows. See https://docs.github.com/en/actions/using-workflows/reusing-workflows . Originally posted by @bschmalhofer in https://github.com/RotherOSS/otobo/issues/3628#issuecomment-2264864549

[bschmalhofer]

Triggering _docker_image_builderrel.yml when a tag is pushed is working. The next step is to set up an reusable workflow, see https://docs.github.com/en/actions/using-workflows/reusing-workflows .

[bschmalhofer]

Turns out that reusable workflows are not a good solution for simply eliminating code duplication in workflows. Local composite actions are a better approach, https://docs.github.com/en/actions/creating-actions/creating-a-composite-action .

[bschmalhofer]

This has been implemented. For activating the workflow the following steps must be taken:

• [ ] Adapt the glob pattern in the on hash from 'test-' to 'rel-'
• [x] Add the workflow and the action to the other branches