Upgrade mediawiki-codesniffer to 52 to unblock Composer

[JeroenDeDauw]

Composer refuses to install php_codesniffer 3.12.2 (CVE-2026-67434), which mediawiki-codesniffer 47 pins, so every job
resolving the extension's own dependencies fails. Version 52 pins the patched 3.13.6, but requires PHP 8.3, so the
standalone unit job drops it on its minimum-PHP leg. Its new property-annotation sniff needs one exclusion for our
@psalm-suppress.

_{AI-authored — Claude Code, Opus 5 (max); one-line ask from @JeroenDeDauw, no revisions; diff not yet human-reviewed; phpcs, PHPStan, Psalm and the unit suite run locally against MW 1.43, and Composer resolution simulated for both the 8.1 and 8.3 legs.}

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 83.41%. Comparing base (a96144d) to head (d7a694d).

Additional details and impacted files

@@            Coverage Diff            @@
##             master      #53   +/-   ##
=========================================
  Coverage     83.41%   83.41%           
  Complexity      416      416           
=========================================
  Files            40       40           
  Lines          1067     1067           
=========================================
  Hits            890      890           
  Misses          177      177           

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