Remove incorrect subclassing of partial.

The type was incorrectly being picked up for this style of subclassing,
and it can be regardless inferred through cls.

pydantic/generics.py

@@ -182,7 +182,11 @@ class B(A[V], Generic[V]):
                     # type is Generic or
                     # base model is already concrete, and will be included transitively.
                     continue
+                elif cls in _assigned_parameters and base_model in _assigned_parameters:
+                    # Subclass will be inferred via cls
+                    continue
                 else:
+                    # print(f'{typevars_map}, {mapped_types}, {mapped_types}, {cls.__parameters__}, {base_model.__parameters__}')
                     base_parameters = tuple([mapped_types[param] for param in base_model.__parameters__])
                     result = base_model.__class_getitem__(base_parameters)
                     if result != base_model and result != cls: