mpi4py: run the spawn and dynamic process tests

[jsquyres]

Split the mpi4py Github Action into 4 parts:

1. build: do everything to build, configure, and install Open MPI and mpi4py
2. run: run all the mpi4py tests with its defaults. As of March 2024, this disables the spawn and dynamic tests, which means that the entire block of tests should pass.
3. run_spawn: run all the mpi4py tests, including the spawn tests. As of March 2024, we know some of these tests are failing.
4. run_dynamic: run all the mpi4py tests, including the dynamic tests. As of March 2024, we know some of these tests are failing.

The spawn and dynamic failures are different, so we split them up and run them separately.

[jsquyres]

@hppritcha @dalcinl I think I finally got the github action in a state where I want it -- it is split up into the 4 parts:

1. Build everything
2. Run mpi4py tests with defaults
3. Run mpi4py tests with spawn included
4. Run mpi4py tests with dynamic included

So we get nice green checkmarks for the first 2, and expected red X's for the latter two.

Splitting into multiple parts did make it a bit more complex, however. E.g., I have to upload and download artifacts between the jobs.

You probably have more experience with GHA's than me. Am I making this too complicated?

[dalcinl]

@jsquyres Take a look here https://github.com/mpi4py/mpi4py-testing/blob/master/.github/workflows/abi.yml

• Build job: you first use pip wheel <mpi4py-directory> to create a wheel file, the you use actions/upload-artifact, as in the last two steps starting here
• Test jobs: You have to checkout the mpi4py repo to get the tests, but rather than building again, you download the built wheel artifact, next you pip install <wheel-file> it, as in the two consecutive steps starting here.

The Open MPI part requires a similar treatment, but as there is no "standard" package involved (unless you to the apt route), I guess you just have to tar+upload and download+untar the prefix install directory. Sorry, I cannot look at the full thing right now to give you better advice.

[jsquyres]

@dalcinl Ah, making a wheel and uploading / downloading that artifact would likely be better. Right now, I'm uploading / downloading $site_packages/mpi4py, which is kinda kludgey. Making a wheel, uploading that, downloading that, and the installing the wheel would definitely be cleaner.

The upload/download artifact functionality supports entire trees -- so I changed installing Open MPI to /opt/openmpi and then upload/download that entire tree (no need to tar it up or make a deb or anything). Good enough for here, I think.

Ok, I'll do the wheel thing and then bring this back to the main OMPI community repo.