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
The following patterns still break mypy:
1. `type[]` at top level fails
2. `tuple[T1, T2]` at top level fails (but `tuple[T1, ...]` is fine)
3. `T1 | Callable[..., T2 | T3]` fails, but only <=3.9
This PR cleans up usage of `Union` and `Optional` outside these patterns.
I just found and fixed a bug in pyright's "missing type arguments" check. When type arguments were omitted for a generic type within a subscript expression, the error was being suppressed. With this bug fixed, I found several new cases where type arguments were missing in stdlib stubs. (#5130)
Co-authored-by: Eric Traut <erictr@microsoft.com>
