[TOOL-3422] Dashboard: Remove unused assets, Add Delete script (#6253)

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## PR-Codex overview
This PR focuses on the deletion of numerous unused asset files from the `apps/dashboard/public/assets` directory and introduces a script for managing the deletion of these files.

### Detailed summary
- Deleted multiple unused asset files from various directories in `apps/dashboard/public/assets`.
- Introduced `deleteUnusedAssets.ts` script to handle the deletion of specified files.
- Added functionality to log deleted files and handle errors when files are not found.

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Author: MananTank