[MM-16353] Migrate Channel.AnalyticsDeletedTypeCount to Sync by default (#11289)

* [MM-16353] Migrate AnalyticsDeletedTypeCount to Sync by default

* refactor: decrease branching

* test: use testify for assertion

app/diagnostics.go

@@ -183,12 +183,12 @@ func (a *App) trackActivity() {
 		directChannelCount = dcc
 	}
 
-	if duccr := <-a.Srv.Store.Channel().AnalyticsDeletedTypeCount("", "O"); duccr.Err == nil {
-		deletedPublicChannelCount = duccr.Data.(int64)
+	if duccr, err := a.Srv.Store.Channel().AnalyticsDeletedTypeCount("", "O"); err == nil {
+		deletedPublicChannelCount = duccr
 	}
 
-	if dpccr := <-a.Srv.Store.Channel().AnalyticsDeletedTypeCount("", "P"); dpccr.Err == nil {
-		deletedPrivateChannelCount = dpccr.Data.(int64)
+	if dpccr, err := a.Srv.Store.Channel().AnalyticsDeletedTypeCount("", "P"); err == nil {
+		deletedPrivateChannelCount = dpccr
 	}
 
 	postsCount, _ = a.Srv.Store.Post().AnalyticsPostCount("", false, false)