misc: run manage.py with python3 (#36224)

debian/chrono-manage

@@ -18,9 +18,9 @@ fi
 
 if test $# -eq 0
 then
-    python ${MANAGE} help
+    python3 ${MANAGE} help
     exit 1
 fi
 
-python ${MANAGE} "$@"
+python3 ${MANAGE} "$@"
 

manage.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 import os
 import sys