Bump mlflow in /nlp/python-sdk-v2/data-science/environments/training

Bumps [mlflow](https://github.com/mlflow/mlflow) from 2.2.1 to 2.3.1.
- [Release notes](https://github.com/mlflow/mlflow/releases)
- [Changelog](https://github.com/mlflow/mlflow/blob/master/CHANGELOG.md)
- [Commits](mlflow/mlflow@v2.2.1...v2.3.1)

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

Signed-off-by: dependabot[bot] <[email protected]>

nlp/python-sdk-v2/data-science/environments/training/requirements.txt

@@ -8,7 +8,7 @@ rouge_score==0.0.4
 sentencepiece==0.1.96
 
 # for metrics reporting/plotting
-mlflow==2.2.1
+mlflow==2.3.1
 azureml-mlflow==1.41.0
 # matplotlib==3.5.2
 # tqdm==4.64.0