build(deps): bump mlflow in /tests/data/serve_resources/mlflow/pytorch

Bumps [mlflow](https://github.com/mlflow/mlflow) from 2.20.3 to 3.1.0.
- [Release notes](https://github.com/mlflow/mlflow/releases)
- [Changelog](https://github.com/mlflow/mlflow/blob/master/CHANGELOG.md)
- [Commits](mlflow/mlflow@v2.20.3...v3.1.0)

---
updated-dependencies:
- dependency-name: mlflow
  dependency-version: 3.1.0
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

tests/data/serve_resources/mlflow/pytorch/requirements.txt

@@ -1,4 +1,4 @@
-mlflow==2.20.3
+mlflow==3.1.0
 astunparse==1.6.3
 cffi==1.16.0
 cloudpickle==2.2.1