generated _version.py contains invalid type annotations on <3.9

[exs-avianello]

Hello! Thank you for all of the work on this package ❤️

I wanted to flag up that since setuptools_scm==8.0.1, the dynamically generated version file contains type hints that are only valid on python >=3.9

# file generated by setuptools_scm
# don't change, don't track in version control
__version__ = version = '0.55.1.dev4'  # type: str
__version_tuple__ = version_tuple = (0, 55, 1, 'dev4')  # type: tuple[int | str, ...]

(python 3.8)
> mypy version.py
version.py:4: error: Unexpected "..."  [misc]
version.py:4: error: "tuple" is not subscriptable, use "typing.Tuple" instead  [misc]
version.py:4: error: Incompatible types in assignment (expression has type "Tuple[int, int, int, str]", variable has type "Tuple[Union[int, str], Any]")  [assignment]
Found 3 errors in 1 file (checked 1 source file)

Unless specifically excluding the version file from type checking, I imagine that this is very likely to lead to broken CI/CD pipelines in most workflows.

I think that removing the inline type annotations from the version file (like in setuptools_scm<8.0.0) or adding a from __future__ import annotations at the top of the file would solve the problem

[exs-avianello]

( Might be worth making sure to have a blank line under the from __future__ import annotations just in case users are running black on that file too :) )

# file generated by setuptools_scm
# don't change, don't track in version control
from __future__ import annotations

__version__ = version = "0.55.1.dev4"  # type: str
__version_tuple__ = version_tuple = (0, 55, 1, "dev4")  # type: tuple[int | str, ...]

[RonnyPfannschmidt]

i wonder if this ought to be a mypy bug as well, i was under the impression the future import was just to stop evaluating, the comments aren't evaluated to begin with

i'll add the future import back