Bump react-router and react-router-dom in /pinning-webui

Bumps [react-router](https://github.com/remix-run/react-router/tree/HEAD/packages/react-router) to 7.12.0 and updates ancestor dependency [react-router-dom](https://github.com/remix-run/react-router/tree/HEAD/packages/react-router-dom). These dependencies need to be updated together.


Updates `react-router` from 7.10.1 to 7.12.0
- [Release notes](https://github.com/remix-run/react-router/releases)
- [Changelog](https://github.com/remix-run/react-router/blob/main/packages/react-router/CHANGELOG.md)
- [Commits](https://github.com/remix-run/react-router/commits/[email protected]/packages/react-router)

Updates `react-router-dom` from 7.10.1 to 7.12.0
- [Release notes](https://github.com/remix-run/react-router/releases)
- [Changelog](https://github.com/remix-run/react-router/blob/main/packages/react-router-dom/CHANGELOG.md)
- [Commits](https://github.com/remix-run/react-router/commits/[email protected]/packages/react-router-dom)

---
updated-dependencies:
- dependency-name: react-router
  dependency-version: 7.12.0
  dependency-type: indirect
- dependency-name: react-router-dom
  dependency-version: 7.12.0
  dependency-type: direct:development
...

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

Author: dependabot[bot]