publish-on-change workflow should use helm client login instead of docker login (#264)

fixes:
https://github.com/kubernetes-sigs/inference-perf/actions/runs/18889068464/job/54103290056

Author: Bslabe123

.github/workflows/publish-on-change.yml

@@ -103,15 +103,11 @@ jobs:
             --version $CHART_VERSION \
             --app-version $APP_VERSION
 
-      - name: Login to Quay.io
-        uses: docker/login-action@v3
-        with:
-          registry: quay.io
-          username: ${{ secrets.QUAY_USERNAME }}
-          password: ${{ secrets.QUAY_PASSWORD }}
-
       - name: Push Helm chart to OCI registry
         run: |
+          # Login to Quay.io Helm registry
+          echo "${{ secrets.QUAY_PASSWORD }}" | helm registry login quay.io -u "${{ secrets.QUAY_USERNAME }}" --password-stdin
+          
           OCI_BASE_URL="oci://quay.io/inference-perf/charts"
           OCI_CHART_REPO="oci://quay.io/inference-perf/charts/inference-perf"
           CHART_VERSION="${{ needs.docker.outputs.chart_version }}"

.github/workflows/publish-on-release.yml

@@ -156,15 +156,17 @@ jobs:
           CHART_VERSION=${GITHUB_REF#refs/tags/v}
           helm package deploy/inference-perf -d helm-releases --version $CHART_VERSION --app-version ${{ env.RELEASE_VERSION }}
 
-      - name: Login to Quay.io
-        uses: docker/login-action@v3
-        with:
-          registry: quay.io
-          username: ${{ secrets.QUAY_USERNAME }}
-          password: ${{ secrets.QUAY_PASSWORD }}
-
       - name: Push Helm chart to OCI registry
         run: |
-          # Remove 'v' prefix from version
-          CHART_VERSION=${GITHUB_REF#refs/tags/v}
-          helm push helm-releases/inference-perf-${CHART_VERSION}.tgz oci://quay.io/inference-perf/charts
+          # Login to Quay.io Helm registry
+          echo "${{ secrets.QUAY_PASSWORD }}" | helm registry login quay.io -u "${{ secrets.QUAY_USERNAME }}" --password-stdin
+        
+          OCI_BASE_URL="oci://quay.io/inference-perf/charts"
+          OCI_CHART_REPO="oci://quay.io/inference-perf/charts/inference-perf"
+          CHART_VERSION=${GITHUB_REF#refs/tags/v} # Remove 'v' prefix from version
+
+          echo "Pushing Helm chart ${CHART_VERSION} to ${OCI_BASE_URL}"
+          helm push helm-releases/inference-perf-${CHART_VERSION}.tgz ${OCI_BASE_URL}
+
+          echo "Tagging Helm chart ${CHART_VERSION} as latest..."
+          helm registry copy "${OCI_CHART_REPO}:${CHART_VERSION}" "${OCI_CHART_REPO}:latest"