Specify a defaultfactory type

Author: adamtheturtle

src/mock_vws/database.py

@@ -67,7 +67,7 @@ class VuforiaDatabase:
     # ``frozen=True`` while still being able to keep the interface we want.
     # In particular, we might want to inspect the ``database`` object's targets
     # as they change via API requests.
-    targets: set[Target] = field(default_factory=set, hash=False)
+    targets: set[Target] = field(default_factory=set[Target], hash=False)
     state: States = States.WORKING
 
     request_quota: int = 100000