correctly handle brackets

.gitea/actions/cleanup/action.yml

@@ -30,7 +30,7 @@ runs:
         sanitize_filename() {
           echo "$1" | \
             tr -d '\000-\037' | \
-            sed -e 's#[][\/:*?"<>|]#-#g' | \
+            sed -e 's#[\\/:*?"<>|]#-#g' | \
             sed -e 's/^[[:space:]]*//' -e 's/[[:space:]]*$//'
         }