chore(build): use dependabot and remove buildx usage

.github/dependabot.yml

@@ -0,0 +1,7 @@
+version: 2
+updates:
+  # Maintain dependencies for GitHub Actions
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "daily"

.github/workflows/docker-image.yml

@@ -10,6 +10,7 @@ on:
     branches: [ "main" ]
 env:
   DOCKERHUB_ORG: elpaasoci
+  OCI_IMAGE: git-branch-heads-resource
 
 jobs:
   build_and_publish:
@@ -31,32 +32,29 @@ jobs:
           registry: ghcr.io
           username: ${{ github.repository_owner }}
           password: ${{ secrets.GITHUB_TOKEN }}
-      -
-        # Setting up Docker Buildx with docker-container driver is required
-        # at the moment to be able to use a subdirectory with Git context
-        name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v2
       -
         name: publish git-branch-heads-resource standard image
         uses: docker/[email protected]
         with:
           push: true
           tags: |
-            ${{env.DOCKERHUB_ORG}}/${{env.IMAGE}}:latest
-            ${{env.DOCKERHUB_ORG}}/${{env.IMAGE}}:${{github.sha}}
+            ${{env.DOCKERHUB_ORG}}/${{env.OCI_IMAGE}}:latest
+            ${{env.DOCKERHUB_ORG}}/${{env.OCI_IMAGE}}:${{github.sha}}
             ghcr.io/${{ github.repository }}:latest
             ghcr.io/${{ github.repository }}:${{github.sha}}
-        env:
-          IMAGE: git-branch-heads-resource
       -
         name: publish git-branch-heads-resource tagged image
         if: github.ref_type == 'tag'
         uses: docker/[email protected]
         with:
           push: true
           tags: |
-            ${{env.DOCKERHUB_ORG}}/${{env.IMAGE}}:${{github.ref_name}}
+            ${{env.DOCKERHUB_ORG}}/${{env.OCI_IMAGE}}:${{github.ref_name}}
             ghcr.io/${{ github.repository }}:${{github.ref_name}}
-        env:
-          IMAGE: git-branch-heads-resource
-
+      -
+        name: Update repo description
+        uses: peter-evans/dockerhub-description@v3
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_PASSWORD }}
+          repository: ${{env.DOCKERHUB_ORG}}/${{env.OCI_IMAGE}}