Thinking level is not supported for this model (Gemini 2.5 Pro)

- Copilot Chat Extension Version:
- VS Code Version: 1.136.1 (system setup)
- OS Version: Windows 11 Pro 25H2
- Feature (e.g. agent/edit/ask mode): agent
- Selected model (e.g. GPT 4.1, Claude 3.7 Sonnet): Gemini 2.5 Pro
- Logs:
```
Sorry, your request failed. Please try again.

Client Request Id: 2024b325-7f86-4118-a435-14f78ae1ca6b

Reason: {"error":{"message":"{\n "error": {\n "code": 400,\n "message": "Thinking level is not supported for this model.",\n "status": "INVALID_ARGUMENT"\n }\n}\n","code":400,"status":"Bad Request"}}: ApiError: {"error":{"message":"{\n "error": {\n "code": 400,\n "message": "Thinking level is not supported for this model.",\n "status": "INVALID_ARGUMENT"\n }\n}\n","code":400,"status":"Bad Request"}} at COn (c:\Program Files\Microsoft VS Code\a44adf7f53\resources\app\extensions\copilot\dist\extension.js:1598:157283) at process.processTicksAndRejections (node:internal/process/task_queues:104:5) at async c:\Program Files\Microsoft VS Code\a44adf7f53\resources\app\extensions\copilot\dist\extension.js:1598:153338 at async YBt.generateContentStream (c:\Program Files\Microsoft VS Code\a44adf7f53\resources\app\extensions\copilot\dist\extension.js:1598:169221) at async OI._makeRequest (c:\Program Files\Microsoft VS Code\a44adf7f53\resources\app\extensions\copilot\dist\extension.js:1599:10033) at async m (c:\Program Files\Microsoft VS Code\a44adf7f53\resources\app\extensions\copilot\dist\extension.js:1599:5592) at async A (c:\Program Files\Microsoft VS Code\a44adf7f53\resources\app\extensions\copilot\dist\extension.js:1599:9706)
```

Steps to Reproduce:

1. Send any prompt using the model Gemini 2.5 Pro