collab: Reconnect to channel notes (#31950)

Closes #31758

Release Notes:

- Fixed channel notes not getting re-connected when a connection to Zed
servers is restored.

---------

Co-authored-by: Kirill Bulatov <mail4score@gmail.com>

crates/collab_ui/src/channel_view.rs

@@ -354,6 +354,10 @@ impl ChannelView {
                 editor.set_read_only(true);
                 cx.notify();
             }),
+            ChannelBufferEvent::Connected => self.editor.update(cx, |editor, cx| {
+                editor.set_read_only(false);
+                cx.notify();
+            }),
             ChannelBufferEvent::ChannelChanged => {
                 self.editor.update(cx, |_, cx| {
                     cx.emit(editor::EditorEvent::TitleChanged);