build(deps-dev): bump react-native in /packages/react-native-executorch

Bumps [react-native](https://github.com/facebook/react-native/tree/HEAD/packages/react-native) from 0.81.5 to 0.84.0.
- [Release notes](https://github.com/facebook/react-native/releases)
- [Changelog](https://github.com/facebook/react-native/blob/main/CHANGELOG.md)
- [Commits](https://github.com/facebook/react-native/commits/v0.84.0/packages/react-native)

---
updated-dependencies:
- dependency-name: react-native
  dependency-version: 0.84.0
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

packages/react-native-executorch/package.json

@@ -76,7 +76,7 @@
     "jest": "^29.7.0",
     "metro-react-native-babel-preset": "^0.77.0",
     "react": "19.1.0",
-    "react-native": "0.81.5",
+    "react-native": "0.84.0",
     "react-native-builder-bob": "^0.40.12",
     "typescript": "~5.9.2"
   },