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

[Terry J. Reedy]

Change by Terry J. Reedy <tjreedy at udel.edu>:


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keywords: +patch
pull_requests: +11298
stage: needs patch -> patch review

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