[release-11.5.4] Dashboard: Fix snapshots for the old arch (#103345)

Dashboard: Fix snapshots for the old arch (#98902)

Fix snapshots for the old arch

(cherry picked from commit 125a11ca99)

Co-authored-by: Haris Rozajac <58232930+harisrozajac@users.noreply.github.com>

public/app/features/dashboard/services/DashboardLoaderSrv.ts

@@ -146,6 +146,14 @@ export class DashboardLoaderSrv extends DashboardLoaderSrvBase<DashboardDTO> {
 
     if (type === 'script' && slug) {
       promise = this.loadScriptedDashboard(slug);
+      // needed for the old architecture
+      // in scenes this is handled through loadSnapshot method
+    } else if (type === 'snapshot' && slug) {
+      promise = getDashboardSnapshotSrv()
+        .getSnapshot(slug)
+        .catch(() => {
+          return this._dashboardLoadFailed('Snapshot not found', true);
+        });
     } else if (type === 'public' && uid) {
       promise = backendSrv
         .getPublicDashboardByUid(uid)