[ty]: Consider a class with a dynamic element in its MRO assignable to any subtype of type (#18205)

crates/ty_python_semantic/src/types.rs

@@ -1542,6 +1542,14 @@ impl<'db> Type<'db> {
                 true
             }
 
+            (Type::ClassLiteral(class), Type::SubclassOf(_))
+                if class
+                    .iter_mro(db, None)
+                    .any(class_base::ClassBase::is_dynamic) =>
+            {
+                true
+            }
+
             // Every `type[...]` is assignable to `type`
             (Type::SubclassOf(_), _)
                 if KnownClass::Type

crates/ty_python_semantic/src/types/class_base.rs

@@ -303,6 +303,10 @@ impl<'db> ClassBase<'db> {
             }
         }
     }
+
+    pub(crate) const fn is_dynamic(self) -> bool {
+        matches!(self, Self::Dynamic(_))
+    }
 }
 
 impl<'db> From<ClassType<'db>> for ClassBase<'db> {