Martin von Zweigbergk <martinvonz@google.com> [Mon, 22 Mar 2021 13:14:11 -0700] rev 46816
tests: replace some `python` by `"$PYTHON"` to not only use Python 2
I deleted my `python` binary as a test and a few tests started
failing.
Differential Revision: https://phab.mercurial-scm.org/D10250