CI: Add back the PR exclusion for registry login

.github/workflows/docker-publish.yml

@@ -85,12 +85,14 @@ jobs:
       # Login to Docker Registry
       # https://github.com/docker/login-action
       - name: Log into registry ${{ env.REGISTRY }}
+        if: github.event_name != 'pull_request'
         uses: docker/login-action@v3
         with:
           registry: ghcr.io
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
       - name: Login to Docker Hub
+        if: github.event_name != 'pull_request'
         uses: docker/login-action@v3
         with:
           username: ${{ secrets.DOCKERHUB_USERNAME }}