Re-apply our changes over latest main

[arkuhn]

1. Checkout a branch with latest main
2. Re-apply our diffs one by one in order:
   • git cherry-pick a2f73c96371c27cb1106fdda5a99b637add7d482
   • git cherry-pick e47fcd68f45d236b10805f37b617b7e8f6ac5753
   • git cherry-pick 73d6e7ace88fc5c8503a15da9659828137a10047
3. Add a new commit, switching setup.cfg to use the new format _ instead of - - this currently blocks upgrading to 3.11

error: The build backend returned an error
  Caused by: Call to `setuptools.build_meta:__legacy__.prepare_metadata_for_build_wheel` failed (exit status: 1)
[stderr]
    raise InvalidConfigError(
setuptools.errors.InvalidConfigError: Invalid dash-separated key 'description-file' in 'metadata' (setup.cfg), please use the underscore name 'description_file' instead.

hint: This usually indicates a problem with the package or the build environment.
make: *** [compile-requirements] Error 2
(venv) 

4. Updated commit in mamba makefile:

icalendar==5.0.12
git+https://github.com/headway/icalevents.git@0b32bd0e7d47e8bf586e4eacc68cc846a4fac050#egg=icalevents==0.1.26

5. This package now requires poetry-core to build, so I added that in our makefile:

compile-requirements: venv ## Compile requirements.in to requirements.txt
	uv pip install pip-tools==7.4.1 maturin==1.5.1 poetry-core

6. Evidently upstream pins pytz to 2021.3, and we pin it to 2024.1...

  × No solution found when resolving dependencies:
  ╰─▶ Because only icalevents==0.1.26 is available and icalevents==0.1.26 depends on pytz==2021.3, we can conclude that all
      versions of icalevents depend on pytz==2021.3.
      And because you require pytz==2024.1 and icalevents, we can conclude that your requirements are unsatisfiable.
make: *** [compile-requirements] Error 1

I would have liked to just switch us to upstream, but seemingly the behavior still differs (upstream considers this codepath legacy though). I don't have any context on the changes, but it would be cool to write a repro tests for the behavior we added fixed and either a) get the fix(es) submitted upstream or b) switch to upstream if both packages pass the tests.