ci: update E2E workflow for ConfigMap approach

Match deploy-e2e-headlamp.sh changes:
- Remove Docker image build/push steps (no custom images)
- Remove packages:write permission (no GHCR push needed)
- Add kubectl and Helm setup steps
- Deploy script creates ConfigMap from dist/ and uses stock Headlamp image

.github/workflows/e2e.yaml

@@ -9,12 +9,10 @@ on:
 
 permissions:
   contents: read
-  packages: write
 
 env:
   E2E_NAMESPACE: headlamp-e2e
   E2E_RELEASE: headlamp-e2e
-  IMAGE_REPO: ghcr.io/privilegedescalation/headlamp-polaris-e2e
 
 jobs:
   e2e:
@@ -31,29 +29,20 @@ jobs:
           node-version: '22'
           cache: 'npm'
 
+      - name: Setup kubectl
+        uses: azure/setup-kubectl@v4
+
+      - name: Setup Helm
+        uses: azure/setup-helm@v4
+
       - name: Install dependencies
         run: npm ci
 
       - name: Build plugin
         run: npx @kinvolk/headlamp-plugin build
 
-      - name: Build E2E Headlamp image
-        run: |
-          IMAGE_TAG="sha-$(git rev-parse --short HEAD)"
-          echo "IMAGE_TAG=$IMAGE_TAG" >> "$GITHUB_ENV"
-          docker build -f Dockerfile.e2e \
-            -t "${IMAGE_REPO}:${IMAGE_TAG}" .
-
-      - name: Log in to ghcr.io
-        run: echo "${{ secrets.GITHUB_TOKEN }}" | docker login ghcr.io -u "${{ github.actor }}" --password-stdin
-
-      - name: Push E2E image
-        run: docker push "${IMAGE_REPO}:${IMAGE_TAG}"
-
       - name: Deploy E2E Headlamp instance
-        run: |
-          export IMAGE_TAG="${IMAGE_TAG}"
-          scripts/deploy-e2e-headlamp.sh
+        run: scripts/deploy-e2e-headlamp.sh
 
       - name: Load E2E environment
         run: |