ci: fix a ruff complaint and mark update-upstream.py script as executable

Author: rgommers

update-upstream.py

@@ -4,9 +4,10 @@
 import shlex
 import subprocess
 import sys
-import tomllib
 import warnings
 
+import tomllib
+
 
 def _use_colors() -> bool:
     if 'NO_COLOR' in os.environ: