9444 push images

[poikilotherm]

What this PR does / why we need it:

This pull request will enable pushing Dataverse application images from the stable master branch, nightly builds from the unstable development branch and feature builds from pull requests. It will also enable scheduled rebuilds to keep the important/supported tags up to date.

Which issue(s) this PR closes:

• Closes Push dev app images to registries #9444
• Closes Change tag from "stable" to "alpha" on Docker Hub #9539

Special notes for your reviewer:
This is not yet ready for review. We will need to investigate the correct workflow setups in a separate pet project.

Here's the fancy pet project. Works like a charm. https://github.com/poikilotherm/test-image-push-flows

Suggestions on how to test this:
None yet.

Does this PR introduce a user interface change? If mockups are available, please link/include them here:
No.

Is there a release notes update needed for this change?:
Yes. Will be included once it works.

Additional documentation:
None.

[pdurbin]

@poikilotherm @GPortas and I have been discussing this PR and decided to give it a size of 3.

At the sprint planning kickoff just now, I advocated for a column in the global backlog for containerization (and mentioned it's a topic for the working group meeting next week). For now, I put it at the top of the community column.

[poikilotherm]

I added a link to the pet project in the description.

We can simply copy the workflows from there, rename the targets/modules and drop it in here. Probably should add some docs to our container guides how that pipeline works.

[pdurbin]

We agreed to switch from "stable" to something else.

Also, what else is need to move this pull request from "draft" to "ready for review"?

[github-actions]

Pushed preview application image as ghcr.io/gdcc/dataverse:9444-push-images.
Use it by referencing it with its full name as printed above.

[poikilotherm]

@pdurbin I just moved this to ready for review. Someone should take a look at the text and docs. It seems the workflow itself does what we expect it to do. We will only learn about mistakes with the Docker Hub push after merging, when a push build fails.

[poikilotherm]

@GPortas @MellyGray as you'd be the folks mostly reusing this feature of PR-based images, please let me know if having a bot generated comment like shown above is helpful or not.

[pdurbin]

Look great! I left a few comments and suggestions.

[MellyGray]

@GPortas @MellyGray as you'd be the folks mostly reusing this feature of PR-based images, please let me know if having a bot generated comment like shown above is helpful or not.

The bot is really cool! I haven't use this PR image feature yet, but it seems really useful, thanks!

[pdurbin]

Looks good! API tests are passing. Let's give it a whirl!