[issue37437] update vendorized expat to 2.2.7

[miss-islington]

Change by miss-islington <mariatta.wijaya+miss-islington at gmail.com>:


----------
pull_requests: +14288
pull_request: https://github.com/python/cpython/pull/14471

_______________________________________
Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue37437>
_______________________________________