Add explicit test for .from_quertset Any fallback

tests/typecheck/fields/test_related.yml

@@ -663,6 +663,37 @@
                 Transaction().test()
 
 
+-   case: foreign_key_relationship_for_models_with_custom_manager_unsolvable
+    main: |
+        from myapp.models import Transaction
+    installed_apps:
+        - myapp
+    files:
+        -   path: myapp/__init__.py
+        -   path: myapp/models.py
+            content: |
+                from django.db import models
+                from django.db.models.manager import BaseManager
+                class TransactionQuerySet(models.QuerySet):
+                    def custom(self) -> None:
+                        pass
+
+                # Note, that we cannot resolve dynamic calls for custom managers:
+                class Transaction(models.Model):
+                    objects = BaseManager.from_queryset(TransactionQuerySet)
+                    def test(self) -> None:
+                        reveal_type(self.transactionlog_set)
+                        # We use a fallback Any type:
+                        reveal_type(Transaction.objects.custom())
+
+                class TransactionLog(models.Model):
+                    transaction = models.ForeignKey(Transaction, on_delete=models.CASCADE)
+    out: |
+        myapp/models:9: error: `.from_queryset` called from inside model class body
+        myapp/models:11: note: Revealed type is "django.db.models.manager.RelatedManager[myapp.models.TransactionLog]"
+        myapp/models:13: note: Revealed type is "Any"
+
+
 -   case: resolve_primary_keys_for_foreign_keys_with_abstract_self_model
     main: |
         from myapp.models import User