fix: pin devcontainer CLI to 0.71.0 for GHCR auth compat

The latest devcontainers/cli (0.83.0) has a GHCR authentication bug
where it fails to parse the WWW-Authenticate header. Pin to 0.71.0
which previously published successfully.

Co-Authored-By: Claude Opus 4.6 <[email protected]>

Author: bradleybeddoes

.github/workflows/publish-feature.yml

@@ -20,6 +20,6 @@ jobs:
           publish-features: "true"
           base-path-to-features: "./features"
           generate-docs: "true"
-          oci-registry-password: ${{ secrets.GITHUB_TOKEN }}
+          devcontainer-cli-version: "0.71.0"
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}