TST: Remaining GitHub Actions actions

Description

Remaining things to port from .travis.yml:

• ~Caching~ with ccache and .hypothesis. (.hypothesis caching PR opened at #11161, @saimn is interested to look at the rest when he gets the chance). UPDATE: Haven’t seen a real need for caching so far.
  • Formal documentation at https://docs.github.com/en/free-pro-team@latest/actions/guides/caching-dependencies-to-speed-up-workflows (there is a 5 GB hard limit)
  • There is a blog about using ccache in Actions that maybe we can try.
  • ~Do we want to start caching pip dependencies too?~ See https://github.com/actions/cache/blob/main/examples.md#python---pip (The answer is “no” according to https://github.com/astropy/astropy/issues/11038#issuecomment-786770402 .)
• pytest conditions in test modules using TRAVIS env var. See #11128
  • Example: https://github.com/astropy/astropy/blob/f9ba0f8e68abde11e5af05979213e3909c3f6fc7/conftest.py#L29
• ~Slack notification~ (both on success and failure) for cron job. (@saimn tried something but it didn’t work, @Cadair has a cunning plan at https://github.com/astropy/astropy/issues/11038#issuecomment-743229649.) UPDATE: Nothing is happening on this front and no one has asked for it lately.
• Cron:
  • Big-endian s390x architecture with apt (arch: s390x, ASTROPY_USE_SYSTEM_ALL=1) (@astrofrog opened #11045 )
  • ARM64 architecture with apt (arch: arm64, ASTROPY_USE_SYSTEM_ALL=1) (@astrofrog opened #11045 )
• Finally, delete .travis.yml. (@astrofrog opened #11045 )

From .circleci/config.yml:

• 32-bit and parallel (custom astropy.cfg, Python 3.7 -n=4 --durations=50, Python 3.8 py38-test-double). See #11043
• image-tests-mpl302 (@Cadair says no need to port)
• image-tests-mpl310 (@Cadair says no need to port)
• image-tests-mpldev (@Cadair says no need to port)

Things already in Actions we need to fix:

• Allow remote data job to fail. See #11036
• Separate cron jobs into daily and weekly. See #11036
• See if we can add --open-files back to a newer job in future PR. See #11037
• codecov uploads report fine but not reporting back to PR. How to fix? ~Try codecov/codecov-action#84 and see?~ Looks like a a bug on their side that is now fixed.
• Do we still need branch filters? I guess there is no need for now but we can revisit if we change our minds.
• Fix numpy-dev/remote data job failures. ~See #11042~ (Went away on its own when numpy-dev wheel updated.)
• Fix cron job failures. (Might be the same problem as numpy-dev/remote data job above, ~so should wait until #11042 is merged first~ yes it was.)
• Do we need to roll our own [ci skip]? Failed attempts at #11044 and #11129, maybe https://github.com/astropy/astropy/issues/11038#issuecomment-739075305 . See #11168. And now GitHub supports it, so also see #11316
• Find a way to auto-cancel Actions, see https://github.com/astropy/astropy/issues/11038#issuecomment-727070545 . See #11168

Additional ideas:

• Can we tell ci_workflows.yml to run Actions on the PR fork instead of here, but report back the status to the PR anyway? The astropy version reported will be wrong due to lack of tags on the fork and if some jobs require special tokens, they will not work. (@saimn will investigate and he actually meant the opposite, see #11054)
  • ~Blocked by astropy/pytest-astropy-header#31~

Additional context

I milestoned this issue because ideally we should sort everything out by 4.3 release.

See #10388 for more info (e.g., pros, cons, related links).

[pllim]

We have decided not to do caching, as we haven’t found a real need for it and it introduces extra complexity.

As for Slack notification, still haven’t seen a reliable solution that works. If we really want that, please open a new issue.

I think as it is, Actions works pretty well and satisfied our current CI needs.

[jdavies-st]

With the cache, for some reason, pip builds the drizzle wheels with an older, cached version of numpy. I’m not sure why.

Agree that oldest-supported-numpy is the current solution given the lack of tooling to deal with this in pip.