Revert "SSH reconnect reliability (#19398)" (#19440)

This reverts commit 98ecb43b2d.

Tests fail on main?!

Closes #ISSUE

Release Notes:

- N/A

crates/proto/src/proto.rs

@@ -372,7 +372,6 @@ messages!(
     (OpenServerSettings, Foreground),
     (GetPermalinkToLine, Foreground),
     (GetPermalinkToLineResponse, Foreground),
-    (FlushBufferedMessages, Foreground),
 );
 
 request_messages!(
@@ -499,7 +498,6 @@ request_messages!(
     (RemoveWorktree, Ack),
     (OpenServerSettings, OpenBufferResponse),
     (GetPermalinkToLine, GetPermalinkToLineResponse),
-    (FlushBufferedMessages, Ack),
 );
 
 entity_messages!(