Update types.rs

Author: mtshiba

crates/ty_python_semantic/src/types.rs

@@ -4221,7 +4221,9 @@ impl<'db> Type<'db> {
     /// Returns the inferred return type of `self` if it is a function literal.
     fn inferred_return_type(self, db: &'db dyn Db) -> Option<Type<'db>> {
         match self {
-            Type::FunctionLiteral(function_type) => Some(function_type.inferred_return_type(db)),
+            Type::FunctionLiteral(function_type) if !function_type.file(db).is_stub(db) => {
+                Some(function_type.inferred_return_type(db))
+            }
             _ => None,
         }
     }