Drop support for Python 3.10 (around January/April 2027)

Python 3.10 is expected to reach its end-of-life phase in October 2026 (PEP 619). We will remove support in two steps, approximately three and six months after it reached EOL.

How to remove support

Expected January 2027

• Update the version in README.md.
• Update various fields in pyproject.toml.
• Remove 3.10 from CI and test scripts.
• Update stubtest allow lists. Also check whether items can be moved to the common allow lists.
• Remove requires-python >= 3.11 and python-version >= 3.11 from METADATA.toml.
• Remove the version suffix from regression tests ending with -py311.py.
• Remove tomli from requirements-tests.txt.

Expected April 2027

• Remove 3.10 exclusive branches from stubs.
  • Switch EnumType/EnumMeta names in stdlib/enum.pyi, making EnumType the "real" name
• Remove obsolete stdlib modules (see VERSIONS).
  • binhex
  • distutils.command.bdist_msi
• Replace typing_extensions imports.
  • TypeVarTuple
  • Required/NotRequired
  • Self
  • LiteralString
  • dataclass_transform
• Update "Supported type system features" section in CONTRIBUTING.md as necessary.

(Please amend as necessary.)

Empieza con la lista de comprobación de enero de 2027 en README.md, pyproject.toml, CI y los scripts de pruebas, las listas de permitidos de stubtest, METADATA.toml, las pruebas de regresión y requirements-tests.txt. Después revisa la lista de comprobación de abril en stdlib/enum.pyi, VERSIONS, los stubs afectados y CONTRIBUTING.md. Se considera terminado cuando se haya eliminado la compatibilidad con Python 3.10 en ambas fases y se hayan actualizado las pruebas y los metadatos pertinentes.