Add more defaults to the stdlib (#9606)

Continuing work towards #8988.

The first five commits were created using stubdefaulter on various Python versions; the following commits were all created manually by me to fix various problems. The main things this adds that weren't present in #9501 are:

- Defaults in Windows-only modules and Windows-only branches (because I'm running a Windows machine)
- Defaults in non-py311 branches
- Defaults for float parameters
- Defaults for overloads

stdlib/multiprocessing/dummy/connection.pyi

@@ -23,7 +23,7 @@ class Connection:
     ) -> None: ...
     def __init__(self, _in: Any, _out: Any) -> None: ...
     def close(self) -> None: ...
-    def poll(self, timeout: float = ...) -> bool: ...
+    def poll(self, timeout: float = 0.0) -> bool: ...
 
 class Listener:
     _backlog_queue: Queue[Any] | None