Update SerenityOS JBIG2 test files

https://github.com/SerenityOS/serenity/compare/e7e20d48731bf5c196486...b7418e74d3bce24b59f1b

Not sure if there's a way to limit the comparison to just the
Tests/LibGfx/test-inputs/jbig2/json folder:

https://github.com/SerenityOS/serenity/commits/master/Tests/LibGfx/test-inputs/jbig2/json

Contains, among other things, a test for crbug.com/459840703.

Bug: 459840703,42271957
Change-Id: I1284ebfda3cd80aad0bf576b83cd9f0ac7864759
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium_tests/+/138310
Reviewed-by: Lei Zhang <thestig@chromium.org>
Reviewed-by: Nico Weber <thakis@google.com>