Documentation

PR #97875 extended the PyTypeObject structure with a new tp_watch field. It should be documented in the tp slots section, the PyTypeObject struct definition, and the PyTypeObject slots sections of typeobject.rst

Linked PRs

• gh-99767: update PyTypeObject docs for type watchers #99928
• gh-99767: mark PyTypeObject.tp_watched as internal use only in table #100271