CDRIVER-6080 fix stream tracking in /Client/exhaust_cursor/pool (#2110)

* await monitoring connections before proceeding in test

Author: kevinAlbs

src/libmongoc/tests/test-mongoc-exhaust.c

@@ -115,6 +115,17 @@ test_exhaust_cursor(bool pooled)
       pool = test_framework_new_default_client_pool();
       stream_tracker_track_pool(st, pool);
       client = mongoc_client_pool_pop(pool);
+
+      // Wait for all background monitoring connections to be established.
+      mongoc_uri_t *uri = test_framework_get_uri();
+      // Server 4.4 added support for streaming monitoring and has 2 monitoring connections.
+      int monitor_count = test_framework_get_server_version() >= test_framework_str_to_version("4.4") ? 2 : 1;
+      const mongoc_host_list_t *hosts = mongoc_uri_get_hosts(uri);
+      while (hosts) {
+         stream_tracker_assert_eventual_active_count(st, hosts->host_and_port, monitor_count);
+         hosts = hosts->next;
+      }
+      mongoc_uri_destroy(uri);
    } else {
       client = test_framework_new_default_client();
       stream_tracker_track_client(st, client);