Bump vite from 6.2.5 to 6.2.6 in /backend

Bumps [vite](https://github.com/vitejs/vite/tree/HEAD/packages/vite) from 6.2.5 to 6.2.6.
- [Release notes](https://github.com/vitejs/vite/releases)
- [Changelog](https://github.com/vitejs/vite/blob/v6.2.6/packages/vite/CHANGELOG.md)
- [Commits](https://github.com/vitejs/vite/commits/v6.2.6/packages/vite)

---
updated-dependencies:
- dependency-name: vite
  dependency-version: 6.2.6
  dependency-type: indirect
...

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Author: dependabot[bot]