fix(e2e): restore Build plugin step indentation

The RBAC step removal accidentally moved Build plugin to root level.
Fixes YAML parse error that would prevent E2E workflow from running.

.github/workflows/e2e.yaml

@@ -100,4 +100,4 @@ jobs:
         with:
           name: test-results
           path: test-results/
-          retention-days: 7
+          retention-days: 7

deployment/e2e-ci-runner-rbac.yaml

@@ -1,42 +0,0 @@
----
-# e2e-ci-runner-rbac.yaml
-#
-# Grants the GitHub Actions runner's service account (Arc Runners) the minimum
-# permissions needed to deploy/teardown an E2E Headlamp instance in the
-# privilegedescalation-dev namespace.
-#
-# RBAC is managed via Flux from privilegedescalation/infra — do not apply manually.
-# This manifest is a reference copy in the plugin repo.
-
-apiVersion: rbac.authorization.k8s.io/v1
-kind: Role
-metadata:
-  name: e2e-ci-runner
-  namespace: privilegedescalation-dev
-rules:
-  - apiGroups: [""]
-    resources: ["configmaps", "serviceaccounts", "events"]
-    verbs: ["get", "list", "create", "delete"]
-  - apiGroups: ["apps"]
-    resources: ["deployments"]
-    verbs: ["get", "create", "delete"]
-  - apiGroups: [""]
-    resources: ["services"]
-    verbs: ["get", "create", "delete"]
-  - apiGroups: [""]
-    resources: ["pods"]
-    verbs: ["get", "list"]
----
-apiVersion: rbac.authorization.k8s.io/v1
-kind: RoleBinding
-metadata:
-  name: e2e-ci-runner
-  namespace: privilegedescalation-dev
-subjects:
-  - kind: ServiceAccount
-    name: runners-privilegedescalation-gha-rs-no-permission
-    namespace: arc-runners
-roleRef:
-  kind: Role
-  name: e2e-ci-runner
-  apiGroup: rbac.authorization.k8s.io