Bump httpx from 0.21.3 to 0.23.0 in /simulation-load-balancer

Bumps [httpx](https://github.com/encode/httpx) from 0.21.3 to 0.23.0.
- [Release notes](https://github.com/encode/httpx/releases)
- [Changelog](https://github.com/encode/httpx/blob/master/CHANGELOG.md)
- [Commits](encode/httpx@0.21.3...0.23.0)

---
updated-dependencies:
- dependency-name: httpx
  dependency-type: direct:production
...

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