chore(ml): added testing and github workflow (#2969)

* added testing

* github action for python, made mypy happy

* formatted with black

* minor fixes and styling

* test model cache

* cache test dependencies

* narrowed model cache tests

* moved endpoint tests to their own class

* cleaned up fixtures

* formatting

* removed unused dep

machine-learning/app/models/facial_recognition.py

@@ -16,8 +16,8 @@ class FaceRecognizer(InferenceModel):
         self,
         model_name: str,
         min_score: float = settings.min_face_score,
-        cache_dir: Path | None = None,
-        **model_kwargs,
+        cache_dir: Path | str | None = None,
+        **model_kwargs: Any,
     ) -> None:
         self.min_score = min_score
         super().__init__(model_name, cache_dir, **model_kwargs)