[docs] [issue23156] Update tix install information in tkinter tix chapter of doc

[Terry J. Reedy]

Terry J. Reedy <tjreedy at udel.edu> added the comment:


New changeset cf27c06229eb4b8280bb5f2b93a57e33163411f4 by Terry Jan Reedy in branch 'master':
bpo-23156: Remove obsolete tix install directions (GH-11595)
https://github.com/python/cpython/commit/cf27c06229eb4b8280bb5f2b93a57e33163411f4


----------

_______________________________________
Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue23156>
_______________________________________