build(python): bump minimum Python version to 3.9

[d33bs]

Description

This PR bumps the minimum Python version required by Pycytominer to 3.9 (3.8 will no longer be compatible). Python 3.8 is end-of-life as of this month and there are related dependency issues which could possibly be resolved by removing Python 3.8 as a minimum version.

Thanks for any feedback!

Closes #433

What is the nature of your change?

• [ ] Bug fix (fixes an issue).
• [x] Enhancement (adds functionality).
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected).
• [ ] This change requires a documentation update.

Checklist

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[codecov-commenter]

Codecov Report

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

Project coverage is 94.73%. Comparing base (e8880bc) to head (09b9cef).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #464 +/- ## ========================================== - Coverage 94.74% 94.73% -0.01% ========================================== Files 57 57 Lines 3156 3155 -1 ========================================== - Hits 2990 2989 -1 Misses 166 166 ``` | [Flag](https://app.codecov.io/gh/cytomining/pycytominer/pull/464/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=cytomining) | Coverage Δ | | |---|---|---| | [unittests](https://app.codecov.io/gh/cytomining/pycytominer/pull/464/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=cytomining) | `94.73% <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=cytomining#carryforward-flags-in-the-pull-request-comment) to find out more.

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[d33bs]

Can you update this line to py39 and rerun ruff for the new changes?

Thanks @kenibrewer ! I've just added changes which bump the ruff target version and make related typing changes.

@d33bs - is it worth also addressing https://github.com/cytomining/pycytominer/issues/435 here (or soon)?

Thanks @gwaybio ! My feeling is that Python 3.12 could possibly have surprises for us that lead to more complex changes or decision-making (I don't know of anything off-hand, but I expect something could pop up). This might be over-doing it, but as a result, I think it might be good to keep those changes in an adjacent PR.