repo: update to 2.3 launcher

This pulls the latest version from upstream.  Largely should be
bugfixes, but there's a few new hot features too!

Bug: https://crbug.com/gerrit/10418
Test: `repo sync` still works
Change-Id: Icd901b490857083f047ce900990769efdf5f269b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/2052975Reviewed-by: Michael Mortensen <mmortensen@google.com>
Commit-Queue: Mike Frysinger <vapier@chromium.org>