Anki broken with Python 3.9

[Bikutoso]

System

• xuname:
  Void 5.13.19_1 x86_64 GenuineIntel notuptodate rrrmFFFF
• package:
  anki-2.1.15_4
  python3-3.9.7_1

Expected behavior

Entering an answer should show the result without any errors.

Actual behavior

Gives this error after entering an answer.

Caught exception:
  File "/usr/share/anki/aqt/webview.py", line 322, in handler
    cb(val)
  File "/usr/share/anki/aqt/reviewer.py", line 461, in _onTypedAnswer
    self._showAnswer()
  File "/usr/share/anki/aqt/reviewer.py", line 217, in _showAnswer
    a = self._mungeQA(a)
  File "/usr/share/anki/aqt/reviewer.py", line 156, in _mungeQA
    return self.typeAnsFilter(mungeQA(self.mw.col, buf))
  File "/usr/share/anki/aqt/reviewer.py", line 306, in typeAnsFilter
    return self.typeAnsAnswerFilter(buf)
  File "/usr/share/anki/aqt/reviewer.py", line 362, in typeAnsAnswerFilter
    cor = parser.unescape(cor)
<class 'AttributeError'>: 'HTMLParser' object has no attribute 'unescape'

Steps to reproduce the behavior

Enter an answer in any deck with new/due cards.

Additional Information

Someone has already reported this bug to Gentoo Linux, they have created a patch that does also work in Void.

[ericonr]

It's hacktoberfest, so opening a PR with the patch sounds like a great opportunity ;)

[Bikutoso]

#33287
I think i did this correctly.