fix: sort dag processing stats by last_runtime (apache#37302)

* fix: sort dag processing stats by last_runtime

* Update airflow/dag_processing/manager.py

Co-authored-by: Andrey Anshin <Andrey.Anshin@taragol.is>

---------

Co-authored-by: Jarek Potiuk <jarek@potiuk.com>
Co-authored-by: Andrey Anshin <Andrey.Anshin@taragol.is>

airflow/dag_processing/manager.py

@@ -849,7 +849,7 @@ def _log_file_processing_stats(self, known_file_paths):
             rows.append((file_path, processor_pid, runtime, num_dags, num_errors, last_runtime, last_run))
 
         # Sort by longest last runtime. (Can't sort None values in python3)
-        rows.sort(key=lambda x: x[3] or 0.0)
+        rows.sort(key=lambda x: x[5] or 0.0, reverse=True)
 
         formatted_rows = []
         for file_path, pid, runtime, num_dags, num_errors, last_runtime, last_run in rows: