Add LUCI labels for the commit queue:
go/luci/newroot/getting_started/1_project_setup#additional-gerrit-configuration-for-later.
This should enable testing trybots on the master and
release-branch.go1.20 branch of the Go repo.

Change-Id: I9a83826712731e4f27d17dac09101f430cc2c309
Reviewed-on: https://go-review.googlesource.com/c/All-Projects/+/468955
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>