Bump react-router from 6.20.1 to 6.21.1 (#63)

Bumps [react-router](https://github.com/remix-run/react-router/tree/HEAD/packages/react-router) from 6.20.1 to 6.21.1.
- [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)

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

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

package.json

@@ -22,7 +22,7 @@
     "react": "^18.2.0",
     "react-dom": "^18.2.0",
     "react-ga": "^3.3.1",
-    "react-router": "^6.20.1",
+    "react-router": "^6.21.1",
     "react-router-dom": "^6.21.0",
     "react-router-hash-link": "^2.4.3",
     "react-waypoint": "^10.3.0",