Relax PyYAML constraints in MLflow server

[jtisbell4]

Relax PyYAML constraints in MLflow server

[PennyXQZ]

I meet the same mismatch warning as follow:

2024/06/05 14:33:21 WARNING mlflow.utils.requirements_utils: Detected one or more mismatches between the model's dependencies and the current Python environment:
 - pyyaml (current: 5.4.1, required: pyyaml==6.0.1)
To fix the mismatches, call `mlflow.pyfunc.get_model_dependencies(model_uri)` to fetch the model's environment and install dependencies using the resulting environment file.
2024/06/05 14:33:21 WARNING mlflow.utils.requirements_utils: Detected one or more mismatches between the model's dependencies and the current Python environment:
 - pyyaml (current: 5.4.1, required: pyyaml==6.0.1)
To fix the mismatches, call `mlflow.pyfunc.get_model_dependencies(model_uri)` to fetch the model's environment and install dependencies using the resulting environment file.

'pyyaml==6.0.1' was collected and built during conda env setting up at first, but degraded to 'PyYAML-5.4.1' as limitation by 'requirements.txt'.