Documentation: ext4.rst: remove obsolete descriptions of noacl/nouser_xattr options

These have been deprecated for a decade[1] and removed two years ago[2].
1: f7048605
2: 2d544ec9

Signed-off-by: Stefan Tauner <stefan.tauner@gmx.at>
Link: https://patch.msgid.link/20240728003433.2566649-1-stefan.tauner@gmx.at


Signed-off-by: Theodore Ts'o <tytso@mit.edu>