Another attempt to make skopeo just inspect images

Signed-off-by: Pablo Zmdl <pablo@nextcloud.com>

.ci/update-test-container-image-reference.py

@@ -43,6 +43,7 @@ def update_image_digest(content, full_ref, current_digest, file_path):
         "skopeo", "inspect",
         "--override-os", "linux",
         "--no-tags",
+        "--no-creds",
         "--format", "{{.Digest}}",
         f"docker://{full_ref}",
     ])

.github/workflows/update-test-container-image-references.yml

@@ -14,10 +14,7 @@ jobs:
     - name: Install skopeo
       run: sudo apt-get install -y skopeo
     - name: Run update script
-      run: |
-          # Avoid skopeo trying to write to /run/containers/$USER_ID, which it isn't allowed to do in this context.
-          export REGISTRY_AUTH_FILE="$(mktemp)"
-          python3 .ci/update-test-container-image-reference.py
+      run: python3 .ci/update-test-container-image-reference.py
     - name: Create Pull Request
       uses: peter-evans/create-pull-request@5f6978faf089d4d20b00c7766989d076bb2fc7f1 # v7
       with: