implement initialization of approval workflows on exam creation.

src/pages/api/approval-workflows/create.ts

@@ -33,5 +33,5 @@ async function post(req: NextApiRequest, res: NextApiResponse) {
 
     await replaceApprovalWorkflowsByEntities(configuredWorkflows, entitiesIds);
 
-    return res.status(201).json({ ok: true });
+    return res.status(204).end();
 }