Prevent registering type handlers using types that have specified generics (Dict is okay, Dict[str, int] is not)

[56kyle]

Since there is a ton of complexity involved with supporting proper sub type checking for custom registered type sets, for now the plan is to block off the edge case until it becomes an issue.

For example, if I were to run the following:

from pytest_static.parametric import type_handlers

@type_handlers.register(Dict[str, int | str])
def my_instances(base_type: Any, type_args: tuple[Any, ...]) -> Dict[str, int | str]:
    ...

I would get a TypeError because I gave Dict[str, int | str] as the type to register instead of just Dict.

Ideally in the future this would be perfectly fine and we just match based on whether the current base type + type args are a sub type of the key you provided, but it adds another layer to the issues we are having by taking the cartesian product of possibilities. This might not be as big of a problem down the line if the project can use maturin or if we can find a way to reduce the slow nature of pytest making tests with pytester in the tests for pytest-static. In short performance comes first and this is worth the sacrifice for the time being.