SCons: Integrate annotations as required import

[Repiteo]

• Salvaged from SCons: Bump minimum Python version to 3.8 #98907

With 3.8 being the new minimum Python version, we can now utilize the extremely convenient from __future__ import annotations. Doing so adds functionality from PEP 563¹, postponing the evaluation of type annotations away from define-time. In other words, a lot of hacky workarounds to setup type hints will no longer be necessary; the resulting syntax is much cleaner, even granting functionality which otherwise require 3.9 or 3.10 as their minimum Python version:

# Before
def some_function(env: "SConsEnvironment") -> Optional[Tuple[List[str], Union[int, float]]]:

# After
def some_function(env: SConsEnvironment) -> tuple[list[str], int | float]] | None:

Like the original PR, this adds from __future__ import annotations as a required import. While most files in our repo aren't using this functionality atm, it's still good practice for consistency & won't risk merge conflicts due to being at the very top of the import chain. To ensure that the aforementioned type-hint features are utilized, I've also added UP006², UP007³, and UP037⁴ to the linter ruleset; because our repo never relied on the prior behavior, the first two "unsafe" rules have been marked as "safe" instead.

Besides the above, exactly one other change was made: adding version.py to the list of files excluded from ruff evaluation. I could've instead added an exclusion for the required-import to that file, but I'd rather keep it entirely isolated as it functions as a metadata container. Additionally, as all these modifications are entirely isolated from runtime, no functional changes will be introduced by this PR.

Footnotes

1. https://peps.python.org/pep-0563/ ↩

2. https://docs.astral.sh/ruff/rules/non-pep585-annotation/ ↩

3. https://docs.astral.sh/ruff/rules/non-pep604-annotation/ ↩

4. https://docs.astral.sh/ruff/rules/quoted-annotation/ ↩

[Repiteo]

Superseded by #99640