[Obs AI Assistant] Update evaluation framework KB set up (#221565)

x-pack/solutions/observability/plugins/observability_ai_assistant_app/scripts/evaluation/kibana_client.ts

@@ -169,6 +169,9 @@ export class KibanaClient {
       async () => {
         const response = await this.callKibana<{}>('POST', {
           pathname: '/internal/observability_ai_assistant/kb/setup',
+          query: {
+            inference_id: '.elser-2-elasticsearch',
+          },
         });
         this.log.info('Knowledge base is ready');
         return response.data;