upgrade mypy to v1.10.1

[tdyas]

Upgrade MyPy to v1.10.1 for Pants' own source code.

Overview of issues found:

• Many # type: ignore comments were removed due to improvements in MyPy.
• MyPy wonderfully found uses of dataclasses.replace where the code was using the wrong type for a replaced field (especially egregious since some cases passed in a mutable list where an immutable value was expected to be stored in the (frozen) dataclass).
• MyPy could not infer that FrozenDict implements the SupportsKeysAndGetItem protocol (for whatever reasons) and so I added ignores of dict-item in certain places.
• Upgraded strawberry-graphql which is used by repo-internal plugin pants-plugins/pants_explorer/server to work around an ICE in mypy. I also had to add some # type: ignore comments to that module. I have not tested pants_explorer since I did not find a README about how to use it for Pants development.

[cburroughs]

I know reports indicate this doesn't fully fix #18519, but I don't think there is any reason not to do this upgrade. Anything todo before un-drafting?

[tdyas]

I know reports indicate this doesn't fully fix #18519, but I don't think there is any reason not to do this upgrade. Anything todo before un-drafting?

Still need to cleanup unused type comments as per this build failure: https://github.com/pantsbuild/pants/actions/runs/9894141143/job/27331097301?pr=21158

[tdyas]

And still not understanding why inclusion of types-setuptools does not fix this error:

src/python/pants/util/pip_requirement.py:10:1: error: Library stubs not installed for "pkg_resources.extern.packaging.requirements"  [import-untyped]
    from pkg_resources.extern.packaging.requirements import (
    ^
src/python/pants/util/pip_requirement.py:10:1: note: Hint: "python3 -m pip install types-setuptools"
src/python/pants/util/pip_requirement.py:10:1: note: (or run "mypy --install-types" to install all missing stub packages)
src/python/pants/util/pip_requirement.py:10:1: note: See https://mypy.readthedocs.io/en/stable/running_mypy.html#missing-imports
Found 1 error in 1 file (checked 1 source file)

But I haven't tracked whether types-setuptools actually has the requisite type stubs.

[tdyas]

Gave up on trying to solve the setuptools type stub issue, just ignored the applicable import from pkg_resources. This is ready for review.

[tdyas]

Merged in main. This is still ready for review. (This upgrades mypy for Pants itself.)

[huonw]

Thanks for doing this!

[huonw]

It looks like it's this or construct that's causing the issues, likely because the {} becomes dict[Never, Never] and that apparently doesn't satisfy SupportsKeysAndGetItem[K, V] with the specific K and V types.

def direct_splat_frozen_only(fd: FrozenDict[str, int]) -> dict[str, int]:
    return {**fd} # okay

def direct_splat_dict_too(fd: FrozenDict[str, int] | dict[str, int]) -> dict[str, int]:
    return {**fd} # okay
    
def or_splat_explicit(fd: FrozenDict[str, int]) -> dict[str, int]:
    empty: dict[str, int] = {}
    return {**(fd or empty)} # okay

def or_splat_implicit(fd: None | FrozenDict[str, int]) -> dict[str, int]:
    return {**(fd or {})} # error: Unpacked dict entry 0 has incompatible type "FrozenDict[str, int] | dict[Never, Never]"; expected "SupportsKeysAndGetItem[str, int]"  [dict-item]

https://mypy-play.net/?mypy=latest&python=3.12&gist=661f39bc47fc9b1b4f8a80fe0814d1c1

I filed python/mypy#17790

Happy to go with what you've got for now.

[tdyas]

Interesting. Yeah, let's ignore it for now. If and when it gets fixed upstream, we should get a "unused type ignore" error once the ignore is no longer necessary.