Simplify handling of syncing versions

Currently whenever a channel changes we send a huge amount of data to
each member. This is the first step in reducing that

Co-Authored-By: Max <max@zed.dev>
Co-Authored-By: bennetbo <bennetbo@gmx.de>

crates/collab_ui/src/chat_panel.rs

@@ -266,7 +266,7 @@ impl ChatPanel {
             } => {
                 if !self.active {
                     self.channel_store.update(cx, |store, cx| {
-                        store.new_message(*channel_id, *message_id, cx)
+                        store.update_latest_message_id(*channel_id, *message_id, cx)
                     })
                 }
             }