build: add docker image update checker action

.gitea/workflows/nightly.yaml

@@ -5,6 +5,7 @@
 name: BuildTag
 run-name: ${{ gitea.actor }} running CI in the pipeline 🚀
 on:
+  push:
   schedule:
     - cron: "30 2 * * *"
 
@@ -15,17 +16,25 @@ jobs:
     runs-on: cth-ubuntu-latest
     steps:
       - name: Check out repository code
-        uses: actions/checkout@v3
-      - name: Set up docker buildx
-        uses: docker/setup-buildx-action@v3
-        with:
-          driver-opts: |
-            network=giteanet
+        uses: actions/checkout@v4
       - name: Login to Docker Hub
         uses: docker/login-action@v3
         with:
           username: ${{ secrets.DOCKERHUB_USERNAME }}
           password: ${{ secrets.DOCKERHUB_TOKEN }}
+      - name: Check if update available
+        id: checkupdate
+        uses: lucacome/docker-image-update-checker@v2.0.0
+        with:
+          base-image: roundcube/roundcubemail:latest-apache
+          image: zeguigui/roundcubemail:latest-apache 
+      - name: Needs updating ?
+        run: echo "Needs updating: ${{ steps.check.outputs.needs-updating }}"
+      - name: Set up docker buildx
+        uses: docker/setup-buildx-action@v3
+        with:
+          driver-opts: |
+            network=giteanet
       - name: Build and push version
         uses: docker/build-push-action@v5
         env: