Bump react-router

Bumps the npm_and_yarn group with 1 update in the /frontend directory: [react-router](https://github.com/remix-run/react-router/tree/HEAD/packages/react-router).


Updates `react-router` from 7.18.0 to 8.3.0
- [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/react-router@8.3.0/packages/react-router)

---
updated-dependencies:
- dependency-name: react-router
  dependency-version: 8.3.0
  dependency-type: direct:production
  dependency-group: npm_and_yarn
...

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

Author: dependabot[bot]

frontend/package.json

@@ -19,7 +19,7 @@
     "react": "^19.2.7",
     "react-dom": "^19.2.7",
     "react-konva": "^19.2.5",
-    "react-router": "^7.18.0",
+    "react-router": "^8.3.0",
     "styled-components": "^6.4.3"
   },
   "devDependencies": {