Remove support for Python 3.8

[lbianchi-lbl]

Resolves #1462

Changes proposed in this PR:

• Remove Python 3.8 from supported versions in docs and setup.py
• Remove Python 3.8 from CI workflows

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[codecov-commenter]

Codecov Report

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

Project coverage is 76.37%. Comparing base (04fa887) to head (4696841). Report is 27 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #1467 +/- ## ========================================== - Coverage 76.38% 76.37% -0.01% ========================================== Files 394 394 Lines 65108 65108 Branches 14423 14423 ========================================== - Hits 49732 49729 -3 - Misses 12814 12818 +4 + Partials 2562 2561 -1 ```

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[lbianchi-lbl]

Just one non-critical comment.

There is one mention on Python 3.8 on the FAQ page: https://github.com/IDAES/idaes-pse/blob/main/docs/explanations/faq.rst. The pywin32 issue may be relevant to other Python version, in which case we could leave the FAQ as-is.

Good point, I did notice this as well and opted for leaving it in for the same reason you mentioned. I propose to leave that in unless someone objects.

[andrewlee94]

@lbianchi-lbl @bpaul4 I suggest we keep the discussion as well, but add a note to indicate that Python 3.8 is no longer officially supported (i.e. make it clear we left this comment there for those who wish to try (or have similar issues), but that we don't guarantee that the rest of the code will work).

[lbianchi-lbl]

@lbianchi-lbl @bpaul4 I suggest we keep the discussion as well, but add a note to indicate that Python 3.8 is no longer officially supported (i.e. make it clear we left this comment there for those who wish to try (or have similar issues), but that we don't guarantee that the rest of the code will work).

@andrewlee94 I've added a note there (and the same to README.md for good measure):