Docker Publishing and other workflow updates

[Zeitsperre]

Summary

Closes #662

Changes

• Replaced bump2version with bump-my-version.
• Updated ReadTheDocs base image to ubuntu-26.04.
• Added metadata fields to Dockerfiles using modern conventions.
• Added cooldowns to Dependabot.
• Set all GitHub Actions to use commit hashes of versions.
• Added a Docker Hub publishing workflow for both Magpie and Twitcher w/MagpieAdapter

[fmigneault]

The hooks/ should be removed since not needed anymore.

[Zeitsperre]

The hooks/ should be removed since not needed anymore.

Are you sure you want these removed? If they still work, you could still have the option to manually upload built images.

[fmigneault]

Are you sure you want these removed? If they still work, you could still have the option to manually upload built images.

Hooks are part of the automated build (https://docs.docker.com/docker-hub/repos/manage/builds/advanced/), I expect them to not be functional anymore once it is fully retired.

I think its ok anyway. There are make targets for build/push each of them if needed manually, and the CI should take care of them for releases. I would actually rather make sure DockerHub doesn't do duplicate auto-builds that the CI should do in the meantime will the features still exists.

[fmigneault]

Is this still needed?