PYTHONEXECUTABLE envvar incorrectly doc'd as mac-only and ignored by -E/-I

[rickeylev]

Documentation

The documentation for the PYTHONEXECUTABLE environment variable incorrectly claims that it is Mac-only. This was changed sometime around 3.11.

Additionally, it isn't ignored by the -I and -E flags.

Linked PRs

• gh-133525: doc that PYTHONEXECUTABLE is not Mac-only and respected with -E/-I options #133526