Allow cancel async commands without auth

kitty/remote_control.py

@@ -140,6 +140,13 @@ def is_cmd_allowed(pcmd: Dict[str, Any], window: Optional['Window'], from_socket
     sid = pcmd.get('stream_id', '')
     if sid and active_streams.get(sid, '') == pcmd['cmd']:
         return True
+    if 'cancel_async' in pcmd and pcmd.get('async_id'):
+        # we allow these without authentication as they are sent on error
+        # conditions and we cant have users prompted for these. The worst side
+        # effect of a malicious cancel_async request is that it can prevent
+        # another async request from getting a result, if it knows the async_id
+        # of that request.
+        return True
     pw = pcmd.get('password', '')
     if not pw:
         auth_items = get_options().remote_control_password.get('')