chore(cluster link metrics): remove `received` metric

It's currently not bumped by the connector implementation.

apps/emqx_cluster_link/src/emqx_cluster_link_api.erl

@@ -340,7 +340,6 @@ format_metrics(Node, RouterMetrics, ResourceMetrics) ->
                 'failed' => Get([counters, 'failed'], ResourceMetrics),
                 'dropped' => Get([counters, 'dropped'], ResourceMetrics),
                 'retried' => Get([counters, 'retried'], ResourceMetrics),
-                'received' => Get([counters, 'received'], ResourceMetrics),
 
                 'queuing' => Get([gauges, 'queuing'], ResourceMetrics),
                 'inflight' => Get([gauges, 'inflight'], ResourceMetrics),

apps/emqx_cluster_link/test/emqx_cluster_link_api_SUITE.erl

@@ -526,7 +526,6 @@ t_metrics(Config) ->
                     <<"failed">> := _,
                     <<"dropped">> := _,
                     <<"retried">> := _,
-                    <<"received">> := _,
                     <<"queuing">> := _,
                     <<"inflight">> := _,
                     <<"rate">> := _,
@@ -547,7 +546,6 @@ t_metrics(Config) ->
                             <<"failed">> := _,
                             <<"dropped">> := _,
                             <<"retried">> := _,
-                            <<"received">> := _,
                             <<"queuing">> := _,
                             <<"inflight">> := _,
                             <<"rate">> := _,
@@ -568,7 +566,6 @@ t_metrics(Config) ->
                             <<"failed">> := _,
                             <<"dropped">> := _,
                             <<"retried">> := _,
-                            <<"received">> := _,
                             <<"queuing">> := _,
                             <<"inflight">> := _,
                             <<"rate">> := _,