Generate a tag with fixed image on each merge

[pehala]

Problem

Currently, only the latest tag is built on each merge, which logically uses the latest tag for all associated images. This, however, complicates things for QE because images can change under QE hands and will change depending on when it was installed (e.g. a new image of Limitador might have dropped and will automatically be used).

Solution

Generate a new tag (e.g. based on a commit sha), and in that tag, pin the images to a specific digest, similar to how Authorino and its related repositories already do that.

Side-effects

• This will certainly generate a lot of "junk" in quay repositories
  • Can be addressed when it actually becomes a problem with periodic cleaning
• Hard to propagate changes from Authorino and Limitador to Kuadrant, meaning there would have to be some triggers that would trigger build when Authorino or Limitador changes.
  • Can be done later. For the initial solution, a Kuadrant-only trigger will suffice (e.g. when something in the kuadrant-operator changes, generate a build)
• It is almost like doing a release (without docs, changelog etc.) on every merge, so creating a pipeline now will help with the release process later