CI and documentation changes

[jquast]

In response to AI-generated issues, #275 and #276.

#275: Run "python-only" 3.14 tests w/fetched data (GraphemeBreakTest.txt), a CI regression in 0.9.0
release.

#276: Document more clearly about tabstop behavior with alignment. A naive developer (or AI bot)
would wish that python wcwidth rjust would implicitly expand tabs. Make clear that the results of
rjust() and center() would change tabstop locations, and to suggest to call str.expandtabs()
first. I don't wish to expand tabs in alignment functions, this makes them somewhat "destructive".

Also, a naive developer might think rjust('abcdefghi', 1) should return a string of length 1,
being "destructive", make this crystal clear that it does not. Alignment functions are only "additive".

[codspeed]

Merging this PR will not alter performance

✅ 121 untouched benchmarks

---

_{Comparing jq/bots-demand-changes (26c45df) with master (94891e0)}

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 87.49%. Comparing base (94891e0) to head (26c45df).
⚠️ Report is 1 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #277   +/-   ##
=======================================
  Coverage   87.49%   87.49%           
=======================================
  Files          41       41           
  Lines        5614     5614           
  Branches     1501     1501           
=======================================
  Hits         4912     4912           
  Misses        324      324           
  Partials      378      378           

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