stdlib: Add defaults for positional-only parameters (#9655)

stdlib/_tracemalloc.pyi

@@ -13,5 +13,5 @@ def is_tracing() -> bool: ...
 if sys.version_info >= (3, 9):
     def reset_peak() -> None: ...
 
-def start(__nframe: int = ...) -> None: ...
+def start(__nframe: int = 1) -> None: ...
 def stop() -> None: ...