Update docs/backend-system/building-plugins-and-modules/08-migrating.md

Signed-off-by: Johan Haals <johan.haals@gmail.com>

Co-authored-by: Fredrik Adelöw <freben@gmail.com>
Signed-off-by: Johan Haals <johan@haals.se>

docs/backend-system/building-plugins-and-modules/08-migrating.md

@@ -214,7 +214,7 @@ import { kubernetesClustersSupplierExtensionPoint } from '@backstage/plugin-kube
 
 export const kubernetesGKEClusterSupplier = createBackendModule({
   pluginId: 'kubernetes',
-  moduleId: 'gce.supplier',
+  moduleId: 'gke.supplier',
   register(env) {
     env.registerInit({
       deps: {