Bump react and react-dom in /static-site/app

Bumps [react](https://github.com/facebook/react/tree/HEAD/packages/react) and [react-dom](https://github.com/facebook/react/tree/HEAD/packages/react-dom). These dependencies needed to be updated together.

Updates `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)

Updates `react-dom` 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-dom)

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

Signed-off-by: dependabot[bot] <[email protected]>

static-site/app/package.json

@@ -14,8 +14,8 @@
     "@babel/preset-env": "^7.26.0",
     "@babel/preset-react": "^7.26.3",
     "babel-loader": "^9.2.1",
-    "react": "^18.2.0",
-    "react-dom": "^18.3.1",
+    "react": "^19.0.0",
+    "react-dom": "^19.0.0",
     "webpack": "^5.97.1",
     "webpack-cli": "^6.0.1"
   }