Add CI jobs to upload nightly wheels to Anaconda

[agriyakhetarpal]

Description

[!NOTE] For some of the follow-ups to and requirements for this PR, please read through the thread on https://github.com/pybamm-team/PyBaMM/issues/3251

This PR configures the publish_pypi.yml workflow (maybe we should rename it to publish_wheels.yml now?) to add a job that uploads wheels to Anaconda. Currently, wheels will be uploaded on the same cadence as the workflow, so they are more like "fortnightlies" rather than nightlies.

Fixes #3251

Type of change

Please add a line in the relevant section of CHANGELOG.md to document the change (include PR #) - note reverse order of PR #s. If necessary, also add to the list of breaking changes.

• [x] New feature (non-breaking change which adds functionality)

Key checklist:

• [x] No style issues: $ pre-commit run (or $ nox -s pre-commit) (see CONTRIBUTING.md for how to set this up to run automatically when committing locally, in just two lines of code)
• [x] All tests pass: $ python run-tests.py --all (or $ nox -s tests)
• [x] The documentation builds: $ python run-tests.py --doctest (or $ nox -s doctests)

You can run integration tests, unit tests, and doctests together at once, using $ python run-tests.py --quick (or $ nox -s quick).

Further checks:

• [x] Code is commented, particularly in hard-to-understand areas

[agriyakhetarpal]

This is still a draft because I need to add instructions for how to let people use these nightly wheels in the installation guide. I think I can prepare that locally, but it would make more sense to push those changes when we will have the repository secrets and the custom index configured for uploads (and subsequently downloads). I have shared the details for the procedure with Valentin.

[kratman]

Do we have upload limits on anaconda? Nightly builds would make a lot of releases

[agriyakhetarpal]

Do we have upload limits on anaconda? Nightly builds would make a lot of releases

Yes, there is a 5 GB upload limit, but the action handles deleting releases older than N versions or M days automatically if one pushes multiple versions (N and M can be configured). I forgot to mention here that since we are not configuring any SCM-based versioning for the nightlies, they will be overwritten on each upload and we will not hit any limits.

This is what I had sent to @tinosulzer the other day about the requirements here:

1. A nightly channel to push wheels to, to be filled in anaconda_nightly_upload_organization
2. An API key generated to push to this channel and then added as a repository secret
3. A manual upload for a single wheel to this channel for the first time (any platform/architecture shall work, we can delete it later).

[agriyakhetarpal]

Ready for review now with a preliminary draft of the instructions, all we will need is to update the link when it is ready.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 99.58%. Comparing base (cf09d5e) to head (25da440). Report is 250 commits behind head on develop.

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Additional details and impacted files

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[arjxn-py]

I forgot to mention here that since we are not configuring any SCM-based versioning for the nightlies, they will be overwritten on each upload and we will not hit any limits.

Do we plan to configure any SCM-based versioning?

[agriyakhetarpal]

Do we plan to configure any SCM-based versioning?

Not for now until we migrate to a new build system. If we were to set up setuptools-scm and then we start removing setuptools soon, it's going to cause issues with file inclusion and exclusion later, because scikit-build-core uses different ways to handle that and we would need to add something like versioneer and go through it all over again.

What I will suggest for this right now is to use local version identifiers as noted in PEP 440 to distinguish between PyPI releases and these nightlies, and therefore rename the wheel to add +dev after the version tag and before the platform and ABI tags, similar to what JAX does for its GPU wheels. I'll push another commit to make this change.

[agriyakhetarpal]

Bumping the version for built wheels would require a bit of restructuring in the workflow to update the version before building the nightlies and that means this should probably be done when we have some SCM-based versioning. I think we can go ahead with this workflow right now and (I merged the latest changes from develop just now).

The MO to test the nightlies is described in SPEC-0004, which means that PyBOP as a dependent will be implementing a weekly workflow which downloads the PyBOP and PyBaMM nightly wheels as such, something like:

      - name: Test nightly builds
        run: |
          pip install pybop pybamm --pre --extra-index-url https://pypi.anaconda.org/pybamm-and-friends/simple
          pytest --pyargs pybop  # or any other test invocation command

(cc: @BradyPlanden), and a subsequent step/job can then open an issue for PyBOP about incoming failures due to changes in PyBaMM. It is to be noted that the use of --extra-index-url here rather than --index-url means that we open up indices such as PyPI to search in for the case of downloading PyBaMM's dependencies (NumPy, SciPy, CasADi, etc.) because their wheels would not exist in our own nightly index. If it is needed (which IMO it isn't), we can specify multiple index URLs to test in CI and add the https://pypi.anaconda.org/scientific-python-nightly-wheels/simple index.

Users should also look to use --extra-index-url though, because PyBaMM doesn't have a lot of dependents right now (four, based on GitHub's insights). I probably will have to update the installation guide about this so that they are not misled with not being able to download scipy/numpy/casadi/xarray from our index, but still warn them enough that they should use these command-line flags carefully and at their own discretion.