fix(graphql): Allow nullable prefix fields in types

Updates `source_prefix` and `destination_prefix` fields to be nullable.
This ensures compatibility with cases where prefixes may not be provided.

Fixes: #249

Author: pheus

netbox_acls/graphql/types.py

@@ -66,7 +66,7 @@ class ACLStandardRuleType(NetBoxObjectType):
     """
 
     access_list: Annotated["AccessListType", strawberry.lazy("netbox_acls.graphql.types")]
-    source_prefix: Annotated["PrefixType", strawberry.lazy("ipam.graphql.types")]
+    source_prefix: Annotated["PrefixType", strawberry.lazy("ipam.graphql.types")] | None
 
 
 @strawberry_django.type(
@@ -80,7 +80,7 @@ class ACLExtendedRuleType(NetBoxObjectType):
     """
 
     access_list: Annotated["AccessListType", strawberry.lazy("netbox_acls.graphql.types")]
-    source_prefix: Annotated["PrefixType", strawberry.lazy("ipam.graphql.types")]
+    source_prefix: Annotated["PrefixType", strawberry.lazy("ipam.graphql.types")] | None
     source_ports: List[int] | None
-    destination_prefix: Annotated["PrefixType", strawberry.lazy("ipam.graphql.types")]
+    destination_prefix: Annotated["PrefixType", strawberry.lazy("ipam.graphql.types")] | None
     destination_ports: List[int] | None