Add support for Python 3.12

[hugovk]

Also upgrade Python syntax with pyupgrade --py37-plus and bump GitHub Actions.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Comparison is base (0077927) 97.80% compared to head (17d7b4e) 97.79%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #167 +/- ## ========================================== - Coverage 97.80% 97.79% -0.01% ========================================== Files 8 8 Lines 546 545 -1 ========================================== - Hits 534 533 -1 Misses 12 12 ``` | [Flag](https://app.codecov.io/gh/pescadores/pescador/pull/167/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=pescadores) | Coverage Δ | | |---|---|---| | [unittests](https://app.codecov.io/gh/pescadores/pescador/pull/167/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=pescadores) | `97.79% <100.00%> (-0.01%)` | :arrow_down: | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=pescadores#carryforward-flags-in-the-pull-request-comment) to find out more.

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.