chore(deps): bump the uv group across 1 directory with 3 updates

Bumps the uv group with 2 updates in the /backend directory: [protobuf](https://github.com/protocolbuffers/protobuf) and [urllib3](https://github.com/urllib3/urllib3).


Updates `protobuf` from 6.33.0 to 6.33.5
- [Release notes](https://github.com/protocolbuffers/protobuf/releases)
- [Commits](https://github.com/protocolbuffers/protobuf/commits)

Updates `starlette` from 0.46.1 to 0.38.6
- [Release notes](https://github.com/Kludex/starlette/releases)
- [Changelog](https://github.com/Kludex/starlette/blob/main/docs/release-notes.md)
- [Commits](Kludex/starlette@0.46.1...0.38.6)

Updates `urllib3` from 2.3.0 to 2.6.3
- [Release notes](https://github.com/urllib3/urllib3/releases)
- [Changelog](https://github.com/urllib3/urllib3/blob/main/CHANGES.rst)
- [Commits](urllib3/urllib3@2.3.0...2.6.3)

---
updated-dependencies:
- dependency-name: protobuf
  dependency-version: 6.33.5
  dependency-type: indirect
  dependency-group: uv
- dependency-name: starlette
  dependency-version: 0.38.6
  dependency-type: indirect
  dependency-group: uv
- dependency-name: urllib3
  dependency-version: 2.6.3
  dependency-type: indirect
  dependency-group: uv
...

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Author: dependabot[bot]