lookup manager type via mro

there's a lot going on in the test but this specifically breaks lookup through
`TypeVar` in mypy 1.11 (mypy 1.10 also failed in this way as well -- but was
fixed in python/mypy#17381)

test originally failing with:

```
/tmp/django-stubs/tests/typecheck/models/test_inheritance.yml:114:
E   pytest_mypy_plugins.utils.TypecheckAssertionError: Invalid output:
E   Actual:
E     myapp/models:23: error: Incompatible return value type (got "Bound", expected "T")  [return-value] (diff)
E   Expected:
E     (empty)
```

mypy_django_plugin/transformers/models.py

@@ -326,7 +326,7 @@ def run_with_model_cls(self, model_cls: Type[Model]) -> None:
 
         incomplete_manager_defs = set()
         for manager_name, manager in model_cls._meta.managers_map.items():
-            manager_node = self.model_classdef.info.names.get(manager_name, None)
+            manager_node = self.model_classdef.info.get(manager_name)
             manager_fullname = helpers.get_class_fullname(manager.__class__)
             manager_info = self.lookup_manager(manager_fullname, manager)
 

tests/typecheck/models/test_inheritance.yml

@@ -109,3 +109,44 @@
                         abstract = True
                 class User(Mixin1, Mixin2):
                     name = models.TextField()
+
+-   case: test_manager_typevar_through_bounds
+    main: |
+        from myapp.models import ResultProcessorConcrete
+        reveal_type(ResultProcessorConcrete().f())  # N: Revealed type is "myapp.models.Concrete"
+    installed_apps:
+        -   myapp
+    files:
+        -   path: myapp/__init__.py
+        -   path: myapp/models.py
+            content: |
+                from __future__ import annotations
+
+                from django.db.models import Model
+                from django.db.models.manager import Manager
+                from typing import TypeVar, Generic, ClassVar
+                from typing_extensions import Self
+
+                M = TypeVar("M", bound=Model, covariant=True)
+
+                class BaseManager(Manager[M]): ...
+
+                class Base(Model):
+                    custom_objects: ClassVar[BaseManager[Self]] = BaseManager()
+
+                class Bound(Base): pass
+
+                T = TypeVar("T", bound=Bound)
+
+                class ResultProcessorBase(Generic[T]):
+                    @property
+                    def model_cls(self) -> type[T]:
+                        raise NotImplementedError
+
+                    def f(self) -> T:
+                        return self.model_cls.custom_objects.get()
+
+                class Concrete(Bound): pass
+
+                class ResultProcessorConcrete(ResultProcessorBase[Concrete]):
+                    pass