chore: record lifecycle duration metric to prometheus (#15279)

`autobuild_execution_duration_seconds` keeps track of how long autobuild
takes and exposes it via prometheus histogram

coderd/coderdtest/coderdtest.go

@@ -335,6 +335,7 @@ func NewOptions(t testing.TB, options *Options) (func(http.Handler), context.Can
 		ctx,
 		options.Database,
 		options.Pubsub,
+		prometheus.NewRegistry(),
 		&templateScheduleStore,
 		&auditor,
 		accessControlStore,