The token limit reached callout was shown for all the providers and it
included the burn mode toggle and description. I have made that
conditional to only show for zed provider.

Before this changes
<img width="413" alt="image"
src="https://github.com/user-attachments/assets/b7e177fc-d2e6-4942-8934-39ac8c844649"
/>

After this change:
<img width="404" alt="image"
src="https://github.com/user-attachments/assets/0e091b99-c8e3-4960-8b4d-47170883d224"
/>


Release Notes:

- agent: Fix token limit callout to show burn mode only for zed provider

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Co-authored-by: Danilo Leal <daniloleal09@gmail.com>