feat(ci): no more docker builds on PR-related events

[mistercrunch]

SUMMARY

Speaking with the devexp committee, and in the recent community hall
meeting, it's pretty clear we don't need to build the whole docker
matrix on every PR event. It's somewhat expensive and isn't useful.

One of the reason we did it, from what I've gathered, is we want to
catch if some change breaks the docker build for whatever reason. Now
we may not need to actively prevent this pre-merge as this is unlikely,
yet we can still catch it on master as I'm keeping the push events on
master.

Note that:

• I'm also moving the master push build to be multi-platform (amd+arm)
  as we started doing this for the release builds, which is nice as
  the same image can be used on different archs
• The PR events were not "pushed" or cached in our shared, remote
  dockerhub-hosted repo anyways, they were just kind of dry-runs

Oh one more thing, notice the no-op.yml changes? That's because the
required checks related to branch protection are always based on what's
defined on .asf.yml ON master, meaning i need to add dummy/no-op
checks to get this merged, and those can be cleaned up later on in a
follow up PR. Let me know if you know a better way to deal with this.

[craig-rueda]

How will users be able to test Dockerfile changes without running anything at all? I agree that the whole matrix probably doesn't need to be built, but what's stopping us from just allowing one path at a min to run? We could also remove it from the "required" checks as to not be a blocker

[mistercrunch]

I agree @craig-rueda and adapted to run the "ci" build preset on pull_request, this will only --load since we don't have the creds in that context, but it should validate the build on both amd a arm, which we'll do systematically now across the board as the build matrix and resulting set of tags was getting confusing.

[craig-rueda]

LGTM

[dpgaspar]

This will probably help on #26997. I think that docker-compose.yaml -> x-superset-image: &superset-image apachesuperset.docker.scarf.sh/apache/superset:${TAG:-latest-dev} should point to master-dev now

proposing #27179 (if it makes sense)