libimage-exiftool-perl >= 12.37+dfsg-1: makes test fail

Debians CI reports a failing test if libimage-exiftool-perl >= 12.37+dfsg-1 is installed: https://ci.debian.net/data/autopkgtest/unstable/amd64/m/mat2/17593782/log.gz

The actual error:

=================================== FAILURES ===================================
_______________________ TestCleaning.test_all_parametred _______________________

self = <tests.test_libmat2.TestCleaning testMethod=test_all_parametred>

    def test_all_parametred(self):
        for case in self.data:
            if 'ffmpeg' in case:
                try:
                    video._get_ffmpeg_path()
                except RuntimeError:
                    raise unittest.SkipTest
    
            print('[+] Testing %s' % case['name'])
            target = './tests/data/clean.' + case['name']
            shutil.copy('./tests/data/dirty.' + case['name'], target)
            p1 = case['parser'](target)
    
            for k, v in p1.get_meta().items():
                if k not in case['meta']:
                    continue
                if isinstance(v, dict):
                    for _k, _v in v.items():
                        if _k in case['meta'][k]:
                            self.assertEqual(_v, case['meta'][k][_k])
                else:
                    self.assertEqual(v, case['meta'][k])
    
            p1.lightweight_cleaning = True
            self.assertTrue(p1.remove_all())
    
            p2 = case['parser'](p1.output_filename)
            for k, v in p2.get_meta().items():
>               self.assertIn(k, case['expected_meta'])
E               AssertionError: 'TransparentColor' not found in {}

tests/test_libmat2.py:519: AssertionError

This was reported to me just now via email -- thanks!

Note: We've been here before: #136 (closed)