chore(deps): bump undici from 5.4.0 to 5.5.1 in /packages/backend (#8842)

Bumps [undici](https://github.com/nodejs/undici) from 5.4.0 to 5.5.1.
- [Release notes](https://github.com/nodejs/undici/releases)
- [Commits](https://github.com/nodejs/undici/compare/v5.4.0...v5.5.1

)

---
updated-dependencies:
- dependency-name: undici
  dependency-type: indirect
...

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