### What problem does this PR solve?
The restricted_loads function at
[api/utils/init.py#L215](https://github.com/infiniflow/ragflow/blob/main/api/utils/__init__.py#L215)
is still vulnerable leading via code execution. The main reson is that
numpy module has a numpy.f2py.diagnose.run_command function directly
execute commands, but the restricted_loads function allows users import
functions in module numpy.
### Additional Details
[https://github.com/infiniflow/ragflow/issues/1240](https://github.com/infiniflow/ragflow/issues/1240)
### Type of change
- [ ] Bug Fix (non-breaking change which fixes an issue)
- [ ] New Feature (non-breaking change which adds functionality)
- [ ] Documentation Update
- [ ] Refactoring
- [ ] Performance Improvement
- [ ] Other (please describe):
