autopkgtest regression in Debian testing

The following was reported in Debian (https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1112109):

128s =================================== FAILURES
===================================
128s ____________________________ TestCleaning.test_html
____________________________
128s
128s self = <tests.test_libmat2.TestCleaning testMethod=test_html>
128s
128s def test_html(self):
128s shutil.copy('./tests/data/dirty.html', './tests/data/clean.html')
128s p = web.HTMLParser('./tests/data/clean.html')
128s
128s meta = p.get_meta()
128s self.assertEqual(meta['author'], 'jvoisin')
128s
128s ret = p.remove_all()
128s self.assertTrue(ret)
128s
128s p = web.HTMLParser('./tests/data/clean.cleaned.html')
128s self.assertEqual(p.get_meta(), {})
128s self.assertTrue(p.remove_all())
128s
128s os.remove('./tests/data/clean.html')
128s os.remove('./tests/data/clean.cleaned.html')
128s os.remove('./tests/data/clean.cleaned.cleaned.html')
128s
128s with open('./tests/data/clean.html', 'w') as f:
128s f.write('<title><title><pouet/><meta/></title></title><test/>')
128s > p = web.HTMLParser('./tests/data/clean.html')
128s
128s tests/test_libmat2.py:633:
128s _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
_ _ _ _ _ _ _
128s libmat2/web.py:57: in __init__
128s self.__parser.feed(f.read())
128s /usr/lib/python3.13/html/parser.py:159: in feed
128s self.goahead(0)
128s /usr/lib/python3.13/html/parser.py:228: in goahead
128s k = self.parse_endtag(i)
128s /usr/lib/python3.13/html/parser.py:472: in parse_endtag
128s self.handle_endtag(tag)
128s _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
_ _ _ _ _ _ _
128s
128s self = <libmat2.web._HTMLParser object at 0x7f503704e7b0>, tag = 'title'
128s
128s def handle_endtag(self, tag: str):
128s if not self.__validation_queue:
128s > raise ValueError("The closing tag %s doesn't have a corresponding "
128s "opening one in %s." % (tag, self.filename))
128s E ValueError: The closing tag title doesn't have a corresponding
opening one in ./tests/data/clean.html.
128s
128s libmat2/web.py:133: ValueError