gecko: strict_min_version: 67.0 due to dynamic imports

manifest.json

@@ -64,7 +64,8 @@
   "web_accessible_resources": ["src/assets/javascripts/helpers/*"],
   "browser_specific_settings": {
     "gecko": {
-      "id": "{b7f9d2cd-d772-4302-8c3f-eb941af36f76}"
+      "id": "{b7f9d2cd-d772-4302-8c3f-eb941af36f76}",
+      "strict_min_version": "67.0"
     }
   }
 }