cu-cp: fix unit test failure due to UE destruction concurrent with CU-CP destruction

Author: frankist

include/srsran/ngap/ngap_configuration_helpers.h

@@ -27,7 +27,8 @@ inline srs_cu_cp::ngap_configuration make_default_ngap_config()
   cfg.plmn          = "00101";
   cfg.tac           = 7;
   s_nssai_t slice_cfg;
-  slice_cfg.sst = 1;
+  slice_cfg.sst                  = 1;
+  cfg.ue_context_setup_timeout_s = std::chrono::seconds{2};
   cfg.slice_configurations.push_back(slice_cfg);
 
   return cfg;