Add workaround for publishers not being cleaned up after they got des…

…troyed (foxglove#215)

### Public-Facing Changes
- Add workaround for publishers not being cleaned up after they got
destroyed

### Description
Fixes publishers not being fully destroyed if there is no event
triggering the actual cleanup. See
ros2/rclcpp#2146 (comment)

ros2_foxglove_bridge/src/ros2_foxglove_bridge.cpp

@@ -733,6 +733,11 @@ class FoxgloveBridge : public rclcpp::Node {
     if (clientPublications.empty()) {
       _clientAdvertisedTopics.erase(it);
     }
+
+    // Create a timer that immedeately goes out of scope (so it never fires) which will trigger
+    // the previously destroyed publisher to be cleaned up. This is a workaround for
+    // https://github.com/ros2/rclcpp/issues/2146
+    this->create_wall_timer(1s, []() {});
   }
 
   void clientMessage(const foxglove::ClientMessage& message, ConnectionHandle hdl) {