Added support for PR builds on master

[Fmstrat]

• Add docker JDK builder for PRs into main as a :beta
• Replace openjdk with sapmachine as the original repo is deprecated, and sapmachine is official now
• Use ibm-semeru-runtimes (also official) for JDK/JRE 17 LTS

Held up by #3362

[iBotPeaches]

Possible to use layer/targets? Want to avoid becoming one of those projects that has like 15 Dockerfile files in root.

docker/build-push-action@v4 supports target.

So the dockerfile could evolve into like:

• Base
• Beta
• Prod (?)

So we only have 1.

[Fmstrat]

Yea, I actually started this using INCLUDE+ but since only the absolute latest versions of Docker support it, I stopped that path.

After that I reorganized the Dockerfile but I now notice the install can always happen last, so targets should now work. I'll shift there.

EDIT: I also hate the fill-up of root, so you'll see I moved everything Docker related into ./docker

EDIT 2: Hmm, the problem with target is that we can only stop at one spot. Which means to have one Dockerfile we'd need to do extra steps. I guess we could just build a release vs download one so they're the same.

[Fmstrat]

There we go, a single Dockerfile. Releases will be a bit slower because they'll build, but not really a big deal, and we retain the smaller image size. I can test this more fully once #3362 is solved.

[Fmstrat]

Also, let me know if you'd prefer the beta workflow to be part of build.yml so that if a previous step fails they're connected.

[iBotPeaches]

Also, let me know if you'd prefer the beta workflow to be part of build.yml so that if a previous step fails they're connected.

There is a good deal of duplication, but since the entry point is different (published release vs merged pr) - I imagine that'll be difficult.

I'm guessing what might be easier is a composite workflow action we dump into .github/actions/something and that could do the publishing with inputs given from the respective workflows.

[Fmstrat]

Good point, that being said, it only triggers on a completed PR, so all the tests would have already run against the branch, so it probably doesn't actually matter.

[Fmstrat]

Updated to JDK/JRE 17 LTS. No longer blocked.