Techdebt: add typing to AMIS (#6063)

moto/ec2/models/amis.py

@@ -1,7 +1,7 @@
 import json
 import re
 from os import environ
-from typing import Any, Dict, List, Iterable, Optional, Set
+from typing import Any, Dict, List, Iterable, Optional, Set, cast
 from moto.utilities.utils import load_resource
 from ..exceptions import (
     InvalidAMIIdError,
@@ -21,7 +21,7 @@ from ..utils import (
 
 if "MOTO_AMIS_PATH" in environ:
     with open(environ["MOTO_AMIS_PATH"], "r", encoding="utf-8") as f:
-        AMIS = json.load(f)
+        AMIS: List[Dict[str, Any]] = json.load(f)
 else:
     AMIS = load_resource(__name__, "../resources/amis.json")
 
@@ -161,8 +161,11 @@ class AmiBackend:
         if "MOTO_AMIS_PATH" not in environ:
             for path in ["latest_amis", "ecs/optimized_amis"]:
                 try:
-                    latest_amis = load_resource(
+                    latest_amis = cast(
+                        List[Dict[str, Any]],
+                        load_resource(
                             __name__, f"../resources/{path}/{self.region_name}.json"  # type: ignore[attr-defined]
+                        ),
                     )
                     for ami in latest_amis:
                         ami_id = ami["ami_id"]

moto/utilities/utils.py

@@ -14,7 +14,7 @@ def str2bool(v: Any) -> Optional[bool]:
     return None
 
 
-def load_resource(package: str, resource: str) -> Dict[str, Any]:
+def load_resource(package: str, resource: str) -> Any:
     """
     Open a file, and return the contents as JSON.
     Usage: