Improve two classes which are namedtuples at runtime, but cannot be namedtuples in typeshed (#7429)

stdlib/urllib/parse.pyi

@@ -64,8 +64,10 @@ class _NetlocResultMixinStr(_NetlocResultMixinBase[str], _ResultMixinStr): ...
 class _NetlocResultMixinBytes(_NetlocResultMixinBase[bytes], _ResultMixinBytes): ...
 
 class _DefragResultBase(tuple[Any, ...], Generic[AnyStr]):
-    url: AnyStr
-    fragment: AnyStr
+    @property
+    def url(self) -> AnyStr: ...
+    @property
+    def fragment(self) -> AnyStr: ...
 
 class _SplitResultBase(NamedTuple):
     scheme: str