Builds: index literally what latest-finished queries

src/sql/upgrade-65.sql

@@ -0,0 +1,4 @@
+-- Index more exactly what the latest-finished query looks for.
+create index IndexFinishedSuccessfulBuilds
+  on Builds(id DESC, buildstatus, finished, job, jobset_id)
+  where buildstatus = 0 and finished = 1;