Update WinUIGalleryLanding.PNG #1476 (#1478)

Update WinUIGalleryLanding.PNG #1476

![image](https://github.com/microsoft/WinUI-Gallery/assets/9213496/d98a5205-3ece-4e3f-88c0-604b635c07fd)

## Description
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## Motivation and Context
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## How Has This Been Tested?
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## Screenshots (if appropriate):

## Types of changes
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- [ ] Bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to change)