Add patch for flag

patches/d9.json

@@ -86,6 +86,9 @@
     "drupal/field_group": {
       "#2858336 Token support": "https://www.drupal.org/files/issues/2019-01-15/field_group-tokens_in_classes-2858336-16.patch"
     },
+    "drupal/flag": {
+      "#3238783 Fix flag action": "https://git.drupalcode.org/project/flag/-/merge_requests/29.diff"
+    },
     "drupal/group": {
       "#3223957 Link to content entity": "https://git.drupalcode.org/project/group/-/merge_requests/27.diff"
     },