Dear Maintainer, the keyword argument "encoding" for json.loads() was removed in Python 3.9 [1]. Anyway, upstream code was heavily changed and affected lines disappeared. PWIW, packaging new version of pipx fixes this issue.
Kind Regards. [1] https://sources.debian.org/src/python-pipx/0.12.3.1-3/pipx/Venv.py/#L76
