terbium is a maintenance script server and backend for dbtree
wasat is supposed to be the equivalent of terbium in codfw but not yet a working backend for dbtree
it was removed as one in T162976#3186233 https://gerrit.wikimedia.org/r/#/c/348456/1/hieradata/role/common/cache/misc.yaml
after it was added when dbtree was made active/active in https://gerrit.wikimedia.org/r/#/c/346572/
make wasat a working backend and add it back above once we can.