fix(pdf): extend ligature map with Dutch IJ and PUA glyph U+F0A0 (#3254)

* fix(pdf): extend ligature map with Dutch IJ and PUA glyph U+F0A0

Add two entries missing from the PDF text sanitizer's ligature map:
- U+0132 (IJ) → "IJ" and U+0133 (ij) → "ij": Latin capital/small ligature
  IJ, used in Dutch (e.g. IJssel, IJ becomes IJ at the start of words).
- U+F0A0 → "": a Private-Use Area glyph emitted by some PDF fonts as a
  spurious character with no textual meaning; it is silently discarded.

The _LIGATURE_RE pattern is updated to match these new code points.

Closes #2882

Signed-off-by: Smeet Agrawal <smeetagrawal23@gmail.com>

* style: apply ruff formatter fixes

Signed-off-by: Smeet Agrawal <smeetagrawal23@gmail.com>

* fix: remove accidentally included msexcel tests from ligature branch

Signed-off-by: Smeet Agrawal <smeetagrawal23@gmail.com>

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Signed-off-by: Smeet Agrawal <smeetagrawal23@gmail.com>
Co-authored-by: Smeet Agrawal <smeetagrawal23@gmail.com>