[Challenge view] Remove preview button from Hint drawer

## Description

We already have the preview button in the bottom bar, so perhaps the one in the Hint drawer could be removed?

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  <summary>Screenshot</summary>

<img width="394" alt="Image" src="https://github.com/user-attachments/assets/8cd47aae-2dbf-4fcc-9c16-cf155f6b252f" />

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