Upgrade macOS to Python 3.12 to match Homebrew

[jwnimmer-tri]

Is your feature request related to a problem? Please describe.

Hombrew is adding Python 3.12 support. After it's landed and stabilized, they will switch hombrew's default Python on macOS to be 3.12, at which point Drake should also immediately switch to 3.12 on macOS.

See this query for all of the migration PRs.

Describe the solution you'd like

Prepare the build / CI / etc so that the switch is an easy flip. See prior issue for details (TBD here).

• Switch Drake's default to 3.12 (see [workspace] Update macOS to [email protected] #18262 for precedent): [workspace] Update macOS to [email protected] #21013
• Switch drake-external-examples to 3.12 (see Switch to Python 3.11 on Mac drake-external-examples#248 for precedent): Switch to Python 3.12 on macOS drake-external-examples#285
• Rebuild arm64 provisioned images.
  • ventura: ventura-2024-03-05.orkasi
  • sonoma: sonoma-2024-03-05.orkasi
• Rebuild x86_64 provisioned images.
• Stable release and ship new wheels.

Additional context

See #18252 for the prior issue (Python 3.10 => Python 3.11).

It's possible that fixing #19098 at the same time might also make this easier.

[jwnimmer-tri]

The brew switch PR just landed (Homebrew/homebrew-core#150390), so this ticket is ready to be worked now.

[MarcusSorealheis]

so this ticket is ready to be worked now

🫡

[svenevs]

Ok, the DEE component is fixed up and ready. I intend to rebuild the images this evening after dinner.

@jwnimmer-tri my understanding is all the stamps are in place once I re-approve #21013. So the plan of attack is

1. Have the images ready.
2. Switch Jenkins settings.
3. Merge [workspace] Update macOS to [email protected] #21013, continuous launches and results will come back.
4. Merge Switch to Python 3.12 on macOS drake-external-examples#285

Only snag is if things go wrong in continuous for whatever reason, I won't be able to revert them before nightlies.

[jwnimmer-tri]

That all sounds fine. I'm satisfied to have fix-forward mindset, generally dispreferring any revert.

We have stable releases for people who need stability. It's OK for the macOS infra to be broken for a couple days while we get this major upgrade sorted out.

[svenevs]

Alright, we're off to the races 🏇 Continuous jobs of interest:

• https://drake-jenkins.csail.mit.edu/view/Continuous%20Production/job/mac-arm-ventura-clang-bazel-continuous-release/297/consoleFull
• https://drake-jenkins.csail.mit.edu/view/Continuous%20Production/job/mac-x86-monterey-clang-bazel-continuous-release/1575/consoleFull
• https://drake-jenkins.csail.mit.edu/view/Continuous%20Production/job/mac-arm-sonoma-clang-bazel-continuous-release/224/consoleFull

If those and nightlies pass tomorrow morning, I think we can consider this complete. Thanks for helping get things in motion @MarcusSorealheis!

[svenevs]

Stable release and ship new wheels.

Whoops, sorry. That's the last one, if nightlies pass then the image side should be good.

[jwnimmer-tri]

I think we can call this finished. We don't need to keep it open until the stable tag next week.

I checked the nightly build's wheel files and tgz files, and they all look correct.