tests: Fix cluster faces workflow

Signed-off-by: Marcel Klehr <mklehr@gmx.net>

Author: marcelklehr

.github/workflows/cluster-faces-test.yml

@@ -8,8 +8,7 @@ on:
   push:
     branches:
       - main
-      - stable8
-      - stable9
+      - stable*
     paths:
       - 'lib/**'
       - 'src/**'
@@ -131,9 +130,15 @@ jobs:
           ./occ app:enable -vvv -f ${{ env.APP_NAME }}
           php -S localhost:8080 &
 
-      - name: Install
+      - name: Checkout app
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        with:
+          repository: nextcloud/viewer
+          path: apps/viewer
+
+      - name: Install viewer
         run: |
-          ./occ app:enable -vvv ${{ env.APP_NAME }}
+          ./occ app:enable -vvv viewer
 
       - name: Remove unnecessary models to make space
         run: |