Set namespaced registry properly

.github/workflows/docker_publish.yml

@@ -7,6 +7,7 @@ on:
 
 env:
   REGISTRY: ghcr.io
+  NAMESPACED_REGISTRY: ghcr.io/apollographql/ci-utility-docker-images
 
 jobs:
   calculate-images-to-build:
@@ -31,7 +32,6 @@ jobs:
           echo "changed_dirs=$CHANGED_DIRS" >> "$GITHUB_OUTPUT"
   build-and-push-image:
     runs-on: ubuntu-latest
-    # Sets the permissions granted to the `GITHUB_TOKEN` for the actions in this job.
     permissions:
       contents: read
       packages: write
@@ -58,8 +58,8 @@ jobs:
           echo "platforms=$(cat ${{ github.workspace }}/${{ matrix.changed_dir }}/config.yml | yq '.platforms | join(",")')" >> "$GITHUB_OUTPUT"
       - name: Check Image to Build Does Not Already Exist
         run: |
-          if docker manifest inspect ${{ env.REGISTRY }}/${{ matrix.changed_dir }}:${{ steps.extract_from_config_yaml.outputs.desired_version }} > /dev/null; then
-            echo "The tag "${{ env.REGISTRY }}/${{ matrix.changed_dir }}:${{ steps.extract_from_config_yaml.outputs.desired_version }}" already exists in the repository. Do you need to bump the version in the config.yml?"
+          if docker manifest inspect ${{ env.NAMESPACED_REGISTRY }}/${{ matrix.changed_dir }}:${{ steps.extract_from_config_yaml.outputs.desired_version }} > /dev/null; then
+            echo "The tag "${{ env.NAMESPACED_REGISTRY }}/${{ matrix.changed_dir }}:${{ steps.extract_from_config_yaml.outputs.desired_version }}" already exists in the repository. Do you need to bump the version in the config.yml?"
             exit 1
           fi
       - name: Calculate Version
@@ -73,7 +73,7 @@ jobs:
         id: meta
         uses: docker/metadata-action@v5
         with:
-          images: ${{ env.REGISTRY }}/${{ matrix.changed_dir }}
+          images: ${{ env.NAMESPACED_REGISTRY }}/${{ matrix.changed_dir }}
           tags: |
             type=semver,pattern={{version}},value=v${{ steps.calculate_version.outputs.version }}
             type=sha