Bump lightgbm from 4.5.0 to 4.6.0 in /python/lgbserver

Bumps [lightgbm](https://github.com/microsoft/LightGBM) from 4.5.0 to 4.6.0.
- [Release notes](https://github.com/microsoft/LightGBM/releases)
- [Commits](lightgbm-org/LightGBM@v4.5.0...v4.6.0)

---
updated-dependencies:
- dependency-name: lightgbm
  dependency-version: 4.6.0
  dependency-type: direct:production
...

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Author: dependabot[bot]