Bump react-dev-utils

downstream, [react-dev-utils v11.x.x](https://www.npmjs.com/package/react-dev-utils/v/11.0.4) is subject to a [vulnerability](GHSA-33f9-j839-rf8h). Since the release of 12.x.x, `immer` [has been bumped up](facebook/create-react-app#11364 (comment)) and should resolve the "critical" security alert if it's adopted into Gatsby.

packages/gatsby/package.json

@@ -131,7 +131,7 @@
     "prop-types": "^15.7.2",
     "query-string": "^6.14.1",
     "raw-loader": "^4.0.2",
-    "react-dev-utils": "^11.0.4",
+    "react-dev-utils": "^12.0.1",
     "react-refresh": "^0.9.0",
     "redux": "4.1.2",
     "redux-thunk": "^2.4.0",