Bump xgboost from 1.7.2 to 1.7.3 (#3241)

Bumps [xgboost](https://github.com/dmlc/xgboost) from 1.7.2 to 1.7.3.
- [Release notes](https://github.com/dmlc/xgboost/releases)
- [Changelog](https://github.com/dmlc/xgboost/blob/master/NEWS.md)
- [Commits](https://github.com/dmlc/xgboost/compare/v1.7.2...v1.7.3)

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

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requirements.txt

@@ -29,5 +29,5 @@ tabulate==0.9.0
 taskcluster==46.1.1
 tenacity==8.1.0
 tqdm==4.64.1
-xgboost==1.7.2
+xgboost==1.7.3
 zstandard==0.19.0