update Makefile

Makefile

@@ -58,5 +58,7 @@ git-post-main-pr:
 	git reset --hard main
 
 git-del-branches-w-origin:
-	echo 'Deleting branches not present in origin'
-	git fetch -p ; git branch -r | awk '{print $1}' | egrep -v -f /dev/fd/0 <(git branch -vv | grep origin) | awk '{print $1}' | xargs git branch -D
+	echo 'Deleting branches not present in origin + /dev'
+	# Original command (below) is without \(...\) syntax
+	# git fetch -p ; git branch -r | awk '{print $$1}' | egrep -v -f /dev/fd/0 <\(git branch -vv | grep origin\) | awk '{print $$1}' | xargs git branch -D
+	git branch --merged | grep -v "*" | grep -v "main" | xargs git branch -d