serverless: pytest with local launch won't auto delete

### 🔍 Before submitting the issue

- [x] I have searched among the existing issues
- [x] I am using a Python virtual environment

### 🐞 Description of the bug

When running pytest against serverless test cases with local launch (non-Docker), it will generate hundreds of untracked files locally. And `make test_clean` does not do anything. Maybe `test_cleanup.py` needs to update to include the serverless folder

### 📝 Steps to reproduce

Run pytest with local launch against a test file for serverless.

### 💻 Which operating system are you using?

Windows

### 📀 Which ANSYS version are you using?

_No response_

### 🐍 Which Python version are you using?

3.11

### 📦 Installed packages

```shell
Not relevant.
```

Start with test_cleanup.py and trace how make test_clean selects folders. Reproduce the serverless local-launch pytest case on Windows, then verify that the generated untracked files under the serverless folder are removed by make test_clean.

Written by the indexing model from the issue text.