fix(e2e): remove kubectl apply RBAC step

The RBAC manifest must be pre-applied via Flux (infra repo) by a
privileged actor before the first workflow run. The Arc Runners
service account cannot self-apply RBAC — it has no permissions to
retrieve the Role to patch it.

Fixes PRI-594.

.github/workflows/e2e.yaml

@@ -48,7 +48,7 @@ jobs:
       - name: Install dependencies
         run: npm ci
 
-      - name: Build plugin
+- name: Build plugin
         run: npx @kinvolk/headlamp-plugin build
 
       - name: Deploy E2E Headlamp instance