String type hints used in Annotated should be imported in TYPE_CHECKING section, but ruff remove imports for now.
I think ruff should treat the first argument of Annotated similar to the current behavior for ClassVar.

from types import FunctionType  # `types.FunctionType` imported but unused F401
from typing import Annotated

Func = Annotated["FunctionType", int]

ruff 0.3.0