[common] (frame generators) fix: use Iterable instead of Generator for typing

common/polystar/common/frame_generators/frames_generator_abc.py

 from abc import ABC, abstractmethod
-from typing import Generator
+from typing import Iterable
 
 from polystar.common.models.image import Image
 
 
 class FrameGeneratorABC(ABC):
     @abstractmethod
-    def generate(self) -> Generator[Image]:
+    def generate(self) -> Iterable[Image]:
         pass