chore: drop Python 3.5

[henryiii]

Dropping Python 3.5 support.

• chore: drop Python 3.5 support
• chore: more fstrings with flynt's help
• ci: drop Python 3.5
• chore: bump dependency versions

Description

Suggested changelog entry:

* Removed Python 3.5 support.

[henryiii]

I can fix the deprecation warning I think, and PyPy 3.8 NumPy might be buggy still. I’ll drop PyPy 3.6, it is unsupported.

[henryiii]

Note that you currently cannot combine this with a py::args argument.

I think this was fixed…

[henryiii]

Forgot we have a pytest.ini for some situations. Will have to check.

[henryiii]

I'd rather disallow non-f-strings via pylint, vs. have flynt always running to try to convert them. It's actually only a hair stronger at converting them than pyupgrade unless you pass --aggressive, anyway.

[henryiii]

I left off the Flynt addition, but kept the smart quotes one + fix.

[henryiii]

Any thoughts to the failing valgrind run? Will not be able to work on this more for now.

[henryiii]

We have 3 new errors in valgrind when going from numpy 1.21 to numpy 1.22, so I left this at numpy 1.21 for Python < 3.10. Ready for review.