fix: add type hints to serializer method fields

program/serializers.py

@@ -757,11 +757,11 @@ class TimeSlotSerializer(serializers.ModelSerializer):
         ) + read_only_fields
 
     @staticmethod
-    def get_show_id(obj):
+    def get_show_id(obj) -> int:
         return obj.schedule.show.id
 
     @staticmethod
-    def get_note_id(obj):
+    def get_note_id(obj) -> int:
         return obj.note.id if hasattr(obj, "note") else None
 
     def update(self, instance, validated_data):