perf(core): Make user controller tests faster (no-changelog) (#7819)

Before: `17.949 s`
After: `3.886 s`

Followup to:
https://github.com/n8n-io/n8n/pull/7797#discussion_r1404148034

packages/cli/test/integration/shared/db/workflows.ts

@@ -117,3 +117,6 @@ export async function createWorkflowWithTrigger(
 export async function getAllWorkflows() {
 	return Container.get(WorkflowRepository).find();
 }
+
+export const getWorkflowById = async (id: string) =>
+	Container.get(WorkflowRepository).findOneBy({ id });