chore(deps): bump react from 18.3.1 to 19.0.0 in /_examples/chat (#3417)

Bumps [react](https://github.com/facebook/react/tree/HEAD/packages/react) from 18.3.1 to 19.0.0.
- [Release notes](https://github.com/facebook/react/releases)
- [Changelog](https://github.com/facebook/react/blob/main/CHANGELOG.md)
- [Commits](https://github.com/facebook/react/commits/v19.0.0/packages/react)

---
updated-dependencies:
- dependency-name: react
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

_examples/chat/package.json

@@ -9,7 +9,7 @@
     "graphql-sse": "^2.0.0",
     "graphql-tag": "^2.10.0",
     "graphql-ws": "^5.8.1",
-    "react": "^18.2.0",
+    "react": "^19.0.0",
     "react-dom": "^18.2.0",
     "react-scripts": "^5.0.1",
     "styled-components": "^6.1.8",