Remove unnecessary __all__ annotations (#3357)

stdlib/2/_threading_local.pyi

@@ -1,7 +1,5 @@
 # Source: https://hg.python.org/cpython/file/2.7/Lib/_threading_local.py
-from typing import Any, List
-
-__all__: List[str]
+from typing import Any
 
 class _localbase(object): ...
 

stdlib/2/toaiff.pyi

@@ -4,8 +4,6 @@
 from pipes import Template
 from typing import Dict, List
 
-
-__all__: List[str]
 table: Dict[str, Template]
 t: Template
 uncompress: Template