fix examples tab for dashboard (apache#16253)

(cherry picked from commit a5dbe6a)

superset-frontend/src/views/CRUD/welcome/DashboardTable.tsx

@@ -143,6 +143,12 @@ function DashboardTable({
         operator: 'dashboard_is_favorite',
         value: true,
       });
+    } else if (filterName === 'Examples') {
+      filters.push({
+        id: 'created_by',
+        operator: 'rel_o_m',
+        value: 0,
+      });
     }
     return filters;
   };