(aws_cdk): Allow Python Path objects into functions that need paths

### Describe the feature

Allow using Path object in python for when a path to something is needed.

### Use Case

For example to use a Code.from_asset() function I need to turn my Path object into str. It would be nice to not have to do this cast.

```python
Code.from_asset(str(Path().cwd() / 'aws_infrastructure' / 'lambda_functions')),
```

### Proposed Solution

_No response_

### Other Information

_No response_

### Acknowledgements

- [ ] I may be able to implement this feature request
- [ ] This feature might incur a breaking change

### CDK version used

2.154.1 (build febce9d)

### Environment details (OS name and version, etc.)

Ubuntu 24.04

Start at the Code.from_asset() entry point described in the issue and trace how path arguments are represented across jsii and Python. Check how pathlib.Path values are currently handled, then add coverage showing that a Path can be passed without str(); done means the example works on the stated CDK version without breaking existing string paths.

Written by the indexing model from the issue text.