RUF013 incorrectly emitted on invalid annotation with bare Optional

[Skylion007]

Here is the bad code diff

-        hsdp_device_mesh: Optional = None,
+        hsdp_device_mesh: Optional[Optional] = None,

Obviously, an untyped Optional is fine, and Optional[Optional] doesn't make much sense here as an autofix.

• version ruff 0.7.0
• ruff check RUF013 --select=RUF013 . --fix --unsafe-fixes

[AlexWaygood]

A bare Optional is not a valid type annotation; both mypy and pyright will reject using Optional without type arguments in an annotation:

• https://mypy-play.net/?mypy=latest&python=3.12&gist=6cb9bb283ad911103c5a7ba4c09def98
• https://pyright-play.net/?pythonVersion=3.13&strict=true&code=GYJw9gtgBALgngBwJYDsDmUkQWEMoDyCMSYKAhgDYBQ1AHgFyHGkWVQC8UAcmQKZA

But you're right that the autofix here just makes things worse! I think we should just not emit RUF013 at all here. It's outside the scope of this rule to detect type annotations that are simply invalid, and definitely outside the scope of the rule to try to fix them.

[henryiii]

A bare Optional would be Optional[Any], which is Any | None. Which isn't helpful, since Any already includes None. The ones that are allowed to be bare, like list -> list[Any], still make sense with Any.