Fix detection of Pydantic models in ASTStubGenerator

Author: teplandr

mypy/stubgen.py

@@ -863,9 +863,10 @@ def visit_class_def(self, o: ClassDef) -> None:
             self.dataclass_field_specifier = spec.field_specifiers
         is_pydantic_model = False
         for base_type_expr in o.base_type_exprs:
-            if isinstance(base_type_expr, (NameExpr, MemberExpr)) and self.get_fullname(
-                base_type_expr
-            ).endswith("pydantic.BaseModel"):
+            if (
+                isinstance(base_type_expr, (NameExpr, MemberExpr))
+                and self.get_fullname(base_type_expr) == "pydantic.BaseModel"
+            ):
                 is_pydantic_model = True
                 break
         self.processing_pydantic_model = is_pydantic_model