Test failures related to XMP UUID box with libxml2 2.12.0

[musicinmybrain]

In Fedora Rawhide, we see a number of new test failures related to XMP UUID box. I suspect, but have not proven, that this is related to upgrading libxml2 from 2.11.5 to 2.12.0.

=========================== short test summary info ============================
FAILED tests/test_tiff2jp2.py::TestSuite::test_commandline__capture_display_resolution__tilesize
FAILED tests/test_tiff2jp2.py::TestSuite::test_commandline_capture_display_resolution
FAILED tests/test_tiff2jp2.py::TestSuite::test_commandline_tiff2jp2_xmp_uuid
FAILED tests/test_tiff2jp2.py::TestSuite::test_exclude_tags -   File "<string...
FAILED tests/test_tiff2jp2.py::TestSuite::test_exclude_tags_but_specify_a_bad_tag
FAILED tests/test_tiff2jp2.py::TestSuite::test_exclude_tags_camelcase -   Fil...
FAILED tests/test_tiff2jp2.py::TestSuite::test_exif -   File "<string>", line...
FAILED tests/test_tiff2jp2.py::TestSuite::test_one_component_no_tilesize -   ...
FAILED tests/test_tiff2jp2.py::TestSuite::test_xmp -   File "<string>", line 256
FAILED tests/test_tiff2jp2.py::TestSuite::test_xmp__exclude_XMLPacket -   Fil...
============ 10 failed, 596 passed, 1 skipped, 1 warning in 37.23s =============

The errors look like:

E     File "<string>", line 256
E   lxml.etree.XMLSyntaxError: Extra content at the end of the document, line 256, column 1

Full output is attached as build.log.

[quintusdias]

It's a one-line fix, but I will take a little time to make sure I understand why it has changed.

[musicinmybrain]

Thanks! Release 0.12.9 works for me.