Bus: Tests cleanup (#46025)

* Delete unused bus from usagestats

* Few updates to remove bus from searchusers test

* Fix import

pkg/infra/usagestats/service/service.go

@@ -6,7 +6,6 @@ import (
 	"time"
 
 	"github.com/grafana/grafana/pkg/api/routing"
-	"github.com/grafana/grafana/pkg/bus"
 	"github.com/grafana/grafana/pkg/infra/kvstore"
 	"github.com/grafana/grafana/pkg/infra/log"
 	"github.com/grafana/grafana/pkg/infra/usagestats"
@@ -33,7 +32,7 @@ type UsageStats struct {
 	sendReportCallbacks      []usagestats.SendReportCallbackFunc
 }
 
-func ProvideService(cfg *setting.Cfg, bus bus.Bus, sqlStore *sqlstore.SQLStore, pluginStore plugins.Store,
+func ProvideService(cfg *setting.Cfg, sqlStore *sqlstore.SQLStore, pluginStore plugins.Store,
 	socialService social.Service, kvStore kvstore.KVStore, routeRegister routing.RouteRegister,
 ) *UsageStats {
 	s := &UsageStats{