expand CI pyright to use full python version matrix and fix type errors

[jakkdl]

(oops, meant to create this in my fork at first - sorry for the messiness in the PR)

It's perhaps a bit overkill to run pyright on the full test matrix, but with one backport from 3.11 and one from 3.12 we at least need to run <3.11, 3.11 and 3.12

• Adds type hints to _suppress.py
• replaces usage of Self with TypeVars. Fixes Incorrect Self import breaks pyright type-checking #100
• exclude @overload from coverage

[coveralls]

Pull Request Test Coverage Report for Build 7477159334

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.2%) to 98.373%

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Totals
Change from base Build 7460984080:	-0.2%
Covered Lines:	544
Relevant Lines:	553

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💛 - Coveralls

[jakkdl]

Only warnings raised by pyright now is about missing docstrings, but --verifytypes doesn't return a failing exit code for that.

[jakkdl]

Not sure why coveralls thought this PR reduced coverage by -0.2%, but that made me take a look (after figuring out how to run it locally, since the website ain't displaying the source for me) which made me aware of "@overload" not being excluded. So fixed that as well.

[agronholm]

Does this really require two different typevars? Why?

[jakkdl]

Oops, set the wrong bound on the second one

[jakkdl]

But yeah we need two different TypeVars, the signature of e.g. ExceptionGroup.__new__ and BaseExceptionGroup.__new__ should be different - the former will return a [subclass of] ExceptionGroup, the latter a [subclass of] BaseExceptionGroup.

[jakkdl]

bump? :)

[agronholm]

I'll try to get to this today. I have so many projects to look after.

[agronholm]

Looks mostly fine, just a few changes needed.

[agronholm]

Thanks!