Revert "fix: don't reacquire lock to clear unstable data"

This reverts commit 03dd54c.

zenoh/src/api/session.rs

@@ -1101,14 +1101,14 @@ impl SessionInner {
             let _liveliness_subscribers = std::mem::take(&mut state.liveliness_subscribers);
             let _local_resources = std::mem::take(&mut state.local_resources);
             let _remote_resources = std::mem::take(&mut state.remote_resources);
-            let _tokens: HashMap<Id, Arc<LivelinessTokenState>>;
-            let _matching_listeners: HashMap<Id, Arc<MatchingListenerState>>;
+            drop(state);
             #[cfg(feature = "unstable")]
             {
-                _tokens = std::mem::take(&mut state.tokens);
-                _matching_listeners = std::mem::take(&mut state.matching_listeners);
+                let mut state = zwrite!(self.state);
+                let _tokens = std::mem::take(&mut state.tokens);
+                let _matching_listeners = std::mem::take(&mut state.matching_listeners);
+                drop(state);
             }
-            drop(state);
             Ok(())
         })
     }