[issue31170] Update to expat 2.2.4 (expat: utf8_toUtf8 cannot properly handle exhausting buffer)

[STINNER Victor]

Changes by STINNER Victor <victor.stinner at gmail.com>:


----------
pull_requests: +3369

_______________________________________
Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue31170>
_______________________________________