Stdlib: add container default values (#9909)

stdlib/lib2to3/pytree.pyi

@@ -57,7 +57,7 @@ class Leaf(Base):
     value: str
     fixers_applied: list[Any]
     def __init__(
-        self, type: int, value: str, context: _Context | None = None, prefix: str | None = None, fixers_applied: list[Any] = ...
+        self, type: int, value: str, context: _Context | None = None, prefix: str | None = None, fixers_applied: list[Any] = []
     ) -> None: ...
     def __unicode__(self) -> str: ...