Bump pulldown-cmark-to-cmark to 22.0.3

[jtran]

Bug fixes only, instead of #1900. https://github.com/Byron/pulldown-cmark-to-cmark/blob/main/CHANGELOG.md#2203-2026-09-28

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 67.90%. Comparing base (105efca) to head (a2e8729).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1904   +/-   ##
=======================================
  Coverage   67.90%   67.90%           
=======================================
  Files          43       43           
  Lines        8705     8705           
=======================================
  Hits         5911     5911           
  Misses       2794     2794           

Flag	Coverage Δ
unittests	67.90% <ø> (ø)

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