MozPhab 2.16.0 and 2.16.1 Released

[sheehan]

Bugs resolved in Moz-Phab 2.16.1:

• bug 2063077 Run tests in parallel with pytest-xdist
• bug 2063810 Obscure error installing MozPhab

Bugs resolved in Moz-Phab 2.16.0:

• bug 2050987 moz-phab self-update fails when installed via uv tool: “No module named pip”

Discuss these changes in #engineering-workflow on Slack or #Conduit Matrix