ci: upgrade ubuntu 20.04/22.04 runners to 24.04

[joshuarli]

Summary

• Upgrade ubuntu-20.04, ubuntu-22.04 and ubuntu-22.04-arm GitHub Actions runners to ubuntu-24.04 / ubuntu-24.04-arm in .github/
• Where a matrix lists several of these (or already lists ubuntu-24.04), collapse to a single entry instead of duplicating it
• container: images and comments are left alone

Why

GitHub is retiring the Ubuntu 22.04 runner images: deprecation began September 17, 2026
(expect longer queue times) and they are fully unsupported on April 17, 2027, with
scheduled brownouts that deliberately fail ubuntu-22.04 jobs in March and April 2027.
See actions/runner-images#14254.
ubuntu-20.04 was already retired in April 2025, so jobs still on it cannot run.

Review notes

ubuntu-24.04 ships different system software than 22.04 (glibc 2.39, newer compilers
and default Python, different packages). Check any job that depends on an older compiler
or package, an old Python version, or that builds binaries meant to run on older
distributions: those may need to stay on 22.04 until they are migrated deliberately.

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Generated by repomod.

[github-actions]

Codecov Results 📊

✅ 132793 passed | ⏭️ 7220 skipped | Total: 140013 | Pass Rate: 94.84% | Execution Time: 432m 7s

📊 Comparison with Base Branch

Metric	Change
Total Tests	📈 +694
Passed Tests	📈 +695
Failed Tests	📉 -1
Skipped Tests	—

➖ Removed Tests (1)

View removed tests

• test_cache_spans_item_size[True]
  • File: tests.integrations.django.test_cache_module

All tests are passing successfully.

✅ Patch coverage is 100.00%. Project has 2555 uncovered lines.
✅ Project coverage is 90.38%. Comparing base (8afefe8) to head (18ae5f2).

Coverage diff

@@            Coverage Diff             @@
##        master       #PR       +/-##
==========================================
+ Coverage    90.35%    90.38%    +0.03%
==========================================
  Files          202       202         —
  Lines        26551     26551         —
  Branches      9856      9856         —
==========================================
+ Hits         23988     23996        +8
- Misses        2563      2555        -8
- Partials      1487      1486        -1

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