Bump xgboost 1.5.2 to 1.6.0

Bumps [xgboost](https://github.com/dmlc/xgboost) from 1.5.2 to 1.6.0.
- [Release notes](https://github.com/dmlc/xgboost/releases)
- [Changelog](https://github.com/dmlc/xgboost/blob/master/NEWS.md)
- [Commits](dmlc/xgboost@v1.5.2...v1.6.0)

---
updated-dependencies:
- dependency-name: xgboost
  dependency-type: direct:production
  update-type: version-update:semver-minor

requirements.txt

@@ -29,5 +29,5 @@ tabulate==0.8.9
 taskcluster==44.13.0
 tenacity==8.0.1
 tqdm==4.64.0
-xgboost==1.5.2
+xgboost==1.6.0
 zstandard==0.17.0