chore(deps-dev): bump @react-native/metro-config in /demo

Bumps [@react-native/metro-config](https://github.com/facebook/react-native/tree/HEAD/packages/metro-config) from 0.83.1 to 0.84.1.
- [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/v0.84.1/packages/metro-config)

---
updated-dependencies:
- dependency-name: "@react-native/metro-config"
  dependency-version: 0.84.1
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

demo/package-lock.json

@@ -28,7 +28,7 @@
     "@react-native-community/cli-platform-ios": "^20.1.1",
     "@react-native/babel-preset": "0.83.1",
     "@react-native/eslint-config": "0.83.1",
-    "@react-native/metro-config": "0.83.1",
+    "@react-native/metro-config": "0.84.1",
     "@react-native/typescript-config": "0.83.1",
     "@types/react": "^19.2.10",
     "eslint": "^9.39.2",