fix(permissions): handle None response from ACP request_permission

acp_adapter/permissions.py

@@ -63,6 +63,9 @@ def make_approval_callback(
             logger.warning("Permission request timed out or failed: %s", exc)
             return "deny"
 
+        if response is None:
+            return "deny"
+
         outcome = response.outcome
         if isinstance(outcome, AllowedOutcome):
             option_id = outcome.option_id