test(gcp_pubsub): attempt to fix flakiness

https://github.com/emqx/emqx/actions/runs/5125118728/jobs/9218520994?pr=10887#step:8:309
```
  =CRITICAL REPORT==== 30-May-2023::19:19:34.887082 ===
  "check stage" failed: error
  {assertMatch,[{module,emqx_bridge_gcp_pubsub_SUITE},
                {line,1066},
                {expression,"? of_kind ( gcp_pubsub_request_failed , Trace )"},
                {pattern,"[ # { reason := Error , connector := ResourceId } | _ ]"},
                {value,[#{connector =>
                              <<"bridge:gcp_pubsub:emqx_bridge_gcp_pubsub_SUITE0005FCEE15534E9CD4CD02004CF10000">>,
                          msg => gcp_pubsub_request_failed,query_mode => async,
                          reason => {closed,"The connection was lost."},
                          recoverable_error => true,
                          '~meta' =>
                              #{gl => <0.17903.2>,
                                location =>
                                    #Fun<emqx_bridge_gcp_pubsub_connector.19.19548918>,
                                node => 'test@127.0.0.1',pid => <0.19724.2>,
                                time => -576460610660164}}]}]}
  Stacktrace: [{emqx_bridge_gcp_pubsub_SUITE,
                   '-do_econnrefused_or_timeout_test/2-fun-2-',3,
                   [{file,
                        "/__w/emqx/emqx/source/apps/emqx_bridge_gcp_pubsub/test/emqx_bridge_gcp_pubsub_SUITE.erl"},
                    {line,1066}]},
               {emqx_bridge_gcp_pubsub_SUITE,do_econnrefused_or_timeout_test,2,
                   [{file,
                        "/__w/emqx/emqx/source/apps/emqx_bridge_gcp_pubsub/test/emqx_bridge_gcp_pubsub_SUITE.erl"},
                    {line,1022}]}]
```

apps/emqx_bridge_gcp_pubsub/test/emqx_bridge_gcp_pubsub_SUITE.erl

@@ -1062,10 +1062,15 @@ do_econnrefused_or_timeout_test(Config, Error) ->
         fun(Trace) ->
             case Error of
                 econnrefused ->
-                    ?assertMatch(
-                        [#{reason := Error, connector := ResourceId} | _],
-                        ?of_kind(gcp_pubsub_request_failed, Trace)
-                    );
+                    case ?of_kind(gcp_pubsub_request_failed, Trace) of
+                        [#{reason := Error, connector := ResourceId} | _] ->
+                            ok;
+                        [#{reason := {closed, _Msg}, connector := ResourceId} | _] ->
+                            %% _Msg = "The connection was lost."
+                            ok;
+                        Trace0 ->
+                            error({unexpected_trace, Trace0})
+                    end;
                 timeout ->
                     ?assertMatch(
                         [_, _ | _],