Update GHA to use latest Ubuntu

[IndrajeetPatil]

cf. https://twitter.com/GaborCsardi/status/1561694747235958790?s=20&t=5w8alFmjKbCNTBziVXPmMA

[github-actions]

This is how benchmark results would change (along with a 95% confidence interval in relative change) if 80cda4d is merged into main:

•   :ballot_box_with_check:cache_applying: 26.9ms -> 27.2ms [-1.3%, +3.03%]
•   :ballot_box_with_check:cache_recording: 1.27s -> 1.28s [-0.64%, +2.8%]
•   :ballot_box_with_check:without_cache: 3.34s -> 3.35s [-1.71%, +2.24%]

Further explanation regarding interpretation and methodology can be found in the documentation.

[github-actions]

This is how benchmark results would change (along with a 95% confidence interval in relative change) if 9311fe2 is merged into main:

•   :ballot_box_with_check:cache_applying: 28ms -> 27.9ms [-0.98%, +0.56%]
•   :ballot_box_with_check:cache_recording: 1.32s -> 1.32s [-0.71%, +0.18%]
•   :ballot_box_with_check:without_cache: 3.52s -> 3.54s [-0.57%, +1.44%]

Further explanation regarding interpretation and methodology can be found in the documentation.

[lorenzwalthert]

Thanks @IndrajeetPatil