Let's update to python3 and/or replace python libraries we still need with their golang equivalents.

EDIT(spiffxp): took a guess at the list of things to convert by looking for /usr/bin/env python$

• boskos/janitor/gcp_janitor.py
• experiment/bilge.py (experiment/bilge - upgrade py2 -> py3 #13777)
• experiment/find_developers.py (experiment/find_developers - upgrade py2 -> py3 #13778)
• experiment/fix_testgrid_config.py (experiment/fix_testgrid_config - upgrade py2 -> py3 #13787)
• experiment/flakedetector.py (experiment/flakedetector - upgrade py2 -> py3 #13783)
• experiment/generate_tests.py (experiment/generate_tests - upgrade py2 -> py3 #13784)
• experiment/get_job_pods.py
• experiment/graphql_issue_example.py (experiment/graphql_issue_example - upgrade py2 -> py3 #13786)
• experiment/maintenance/*.py (experiment/maintenance - upgrade py2 -> py3 #13782)
• experiment/parse_build_log.py (experiment/parse_build_log - upgrade py2 -> py3 #13779)
• experiment/prepare_release_branch.py (experiment/prepare_release_branch - upgrade py2 -> py3 #13785)
• hack/*.py (ref: hack - upgrade py2 -> py3, #13164 #13385)
• kettle/*.py
• metrics/*.py (ref: metrics - upgrade py2 -> py3, #13164 #13368, revert: Revert "metrics - upgrade py2 -> py3, #13164" #13540)
• testgrid/conformance/upload_e2e.py (testgrid - upgrade py2 -> py3 #13750)
• triage/*.py (ref: use python (pypy) 3 for triage #13732, triage - upgrade py2 -> py3, #13164 #13380 outstanding)
• velodrome/config.py (velodrome - upgrade py2 -> py3, #13164 #13383)

And some guesses on stuff we may not want to migrate? Or do something other than migrate?

• ❓ gubernator/ - we only use the PR dashboard here, do we want to bother with this?
• ❓ jenkins/bootstrap.* - we consider bootstrap deprecated in favor of pod utils, should we just migrate to them?
• ❓ scenarios/*.py - scenarios are used as part of bootstrap, see above