GH-115322: Add missing audit hooks (GH-115624)

Add extra audit hooks to catch C function calling from ctypes,
reading/writing files through readline and executing external
programs through _posixsubprocess.

* Make audit-tests for open pass when readline.append_history_file is unavailable
* Less direct testing of _posixsubprocess for audit hooks
* Also remove the audit hook from call_cdeclfunction now that _ctypes_callproc does it instead.
* reword the NEWS entry.
* mention readline in NEWS
* add versionchanged markers
* fix audit_events.rst versionadded
* doc lint

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Co-authored-by: Gregory P. Smith <greg@krypto.org>