Use Python 3.12 as reference environment

[crusaderky]

• Blocked by and incorporates Run numba in Python 3.12 CI #10891
• Follow-up: Test against pandas 2.0 #10893

[github-actions]

Unit Test Results

See test report for an extended history of previous test failures. This is useful for diagnosing flaky tests.

     15 files  ± 0       15 suites  ±0   3h 20m 36s ⏱️ + 5m 4s
 13 111 tests + 2   12 180 ✅ + 3     931 💤 ±0  0 ❌  - 1 
162 347 runs  +34  145 793 ✅ +33  16 554 💤 +2  0 ❌  - 1 

Results for commit d1c3cf5. ± Comparison against base commit 67ecd26.

This pull request removes 1 and adds 3 tests. Note that renamed tests count towards both.

dask.tests.test_docs ‑ test_development_guidelines_matches_ci

dask.tests.test_docs ‑ test_development_guidelines_matches_ci[.github/workflows/additional.yml]
dask.tests.test_docs ‑ test_development_guidelines_matches_ci[.github/workflows/upstream.yml]
dask.tests.test_docs ‑ test_development_guidelines_matches_ci[docs/source/develop.rst]

[phofl]

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