Change the App dependency with Server in migrations package (#14804)

Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

app/app.go

@@ -129,9 +129,6 @@ func (a *App) initJobs() {
 	if jobsLdapSyncInterface != nil {
 		a.srv.Jobs.LdapSync = jobsLdapSyncInterface(a)
 	}
-	if jobsMigrationsInterface != nil {
-		a.srv.Jobs.Migrations = jobsMigrationsInterface(a)
-	}
 	if jobsPluginsInterface != nil {
 		a.srv.Jobs.Plugins = jobsPluginsInterface(a)
 	}