Python: geojson and csv not supported

- **azure-ai-agents**:
- **1.2.0b5**:
- **MacOS**:
- **3.12.11**:

**Describe the bug**
In context of the issue https://github.com/microsoft/agent-framework/issues/2469#issuecomment-3589640065

**To Reproduce**
Steps to reproduce the behavior:
```
file = await agents_client.files.upload_and_poll(
file_path="example.geojson",
purpose="assistants"
)

```

Error: Message: Files with extensions [.csv] are not supported for retrieval. Supported file types include: [.c, .cpp, .cs, .css, .doc, .docx, .go, .html, .java, .js, .json, .md, .pdf, .php, .pptx, .py, .rb, .sh, .tex, .ts, .txt].

**Expected behavior**
Upload pdf file

**Screenshots**
If applicable, add screenshots to help explain your problem.

**Additional context**
Add any other context about the problem here.