Drop Python 3.9, test against Python 3.14 preview

[simonw]

---

📚 Documentation preview 📚: https://sqlite-utils--665.org.readthedocs.build/en/665/

[codecov]

Codecov Report

❌ Patch coverage is 95.23810% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 95.46%. Comparing base (094b010) to head (6d96dc2).
⚠️ Report is 6 commits behind head on main.

Files with missing lines	Patch %	Lines
sqlite_utils/cli.py	95.23%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #665      +/-   ##
==========================================
- Coverage   95.60%   95.46%   -0.15%     
==========================================
  Files           8        8              
  Lines        2915     2930      +15     
==========================================
+ Hits         2787     2797      +10     
- Misses        128      133       +5     

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[simonw]

Codex CLI on GPT-5-Codex suggested this as a workaround for:

• Sentinel is passed to type_cast_value pallets/click#3069

[simonw]

It looks like that gross Sentinel hack will become unnecessary once Click 8.3.1 is released with their fix to this issue:

• Sentinel is passed to type_cast_value pallets/click#3069

[simonw]

I'm going to land this and file a separate ticket to remove the Sentinel hack once Click ship their next version.