Fix flaky hand tool integration test

[calixteman]

No description provided.

[timvandermeij]

r=me, with passing CI. Thank you!

(For reference, this should fix the error in https://github.com/mozilla/pdf.js/actions/runs/31818083781/job/94824462869.)

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.16%. Comparing base (4c5155e) to head (3b947e3).
⚠️ Report is 6 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #21785      +/-   ##
==========================================
- Coverage   90.17%   90.16%   -0.02%     
==========================================
  Files         264      264              
  Lines       67268    67268              
==========================================
- Hits        60659    60650       -9     
- Misses       6609     6618       +9     

Flag	Coverage Δ
integrationtest	69.37% <ø> (-0.02%)	⬇️
unittestcli	56.81% <ø> (+<0.01%)	⬆️

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