[Fix] Fix Local Runner Params Save Path

[jnanliu]

Motivation

When multiple tasks are submitted in the cloud server's shared file system, the existing local_runner's logic for saving params.py files can cause conflicts between different tasks (these tasks may have the same pid).

Modification

Modify the save path of params.py to work dir of each task.

Checklist

Before PR:

• Pre-commit or other linting tools are used to fix the potential lint issues.
• Bug fixes are fully covered by unit tests, the case that causes the bug should be added in the unit tests.
• The modification is covered by complete unit tests. If not, please add more unit test to ensure the correctness.
• The documentation has been modified accordingly, like docstring or example tutorials.

[MaiziXiao]

LGTM