Update redo_regressions.yml with last update comment

Added last update comment to the workflow file.

Author: scarlehoff

.github/workflows/redo_regressions.yml

@@ -1,6 +1,8 @@
 name: Redo regressions
 
-# start job only for PRs when a label is added.
+# Last update: 17/03/2026
+
+# start job only for PRs when a label is added
 on:
   pull_request:
     types: [labeled]