[AlexWaygood]

Fixes #16595.

Update the stubs for contains_token_type on email._header_value_parser.TokenList and Terminal and the optional context argument to multiprocessing.context.DefaultContext, both introduced in Python 3.14.9 and 3.15.1, and for _remote_debugging.BinaryWriter.limit_reached, introduced in Python 3.15.1.

The contains_token_type stubs accept None because TokenList.token_type defaults to None and TokenList.contains_token_type checks that value against its arguments; for example, TokenList().contains_token_type(None) returns True. Terminal.contains_token_type accepts None as well because TokenList.contains_token_type(None) can forward the argument to Terminal children.

Related CPython PRs:

• contains_token_type: python/cpython#134271
• DefaultContext: python/cpython#159254
• BinaryWriter.limit_reached: python/cpython#152892

[github-actions]

Diff from mypy_primer, showing the effect of this PR on open source code:

sphinx (https://github.com/sphinx-doc/sphinx)
- sphinx/builders/_epub_base.py:34:1: note: See https://mypy.readthedocs.io/en/stable/running_mypy.html#missing-imports

scipy-stubs (https://github.com/scipy/scipy-stubs)
+ tests/misc/test_submodules_empty.pyi:3: note: See https://mypy.readthedocs.io/en/stable/running_mypy.html#missing-imports