fix: match release workflow to working kube-vip template

Remove broken mv logic and use gh CLI for release creation,
matching the proven workflow from other headlamp plugins.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.github/workflows/release.yaml

@@ -71,10 +71,6 @@ jobs:
           VERSION="${{ inputs.version }}"
           PKG_NAME=$(jq -r .name package.json)
           TARBALL="${PKG_NAME}-${VERSION}.tar.gz"
-          ACTUAL=$(ls *.tar.gz)
-          if [ "$ACTUAL" != "$TARBALL" ]; then
-            mv "$ACTUAL" "$TARBALL"
-          fi
           echo "TARBALL=$TARBALL" >> $GITHUB_ENV
           echo "PKG_NAME=$PKG_NAME" >> $GITHUB_ENV