Fix typo in AccessibilityColorContrastPage.xaml (#1904)

looks like a cut and paste issue or incomplete edit was committed
previously

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## Description
<!--- Describe your changes in detail -->

Just a typo fix in text displayed within the app.

## Motivation and Context
<!--- Why is this change required? What problem does it solve? -->
<!--- If it fixes an open issue, please link to the issue here. -->

Improves understanding and makes text clearer.

## How Has This Been Tested?
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to -->
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manually - it's just UI text.

## Screenshots (if appropriate):

Before:
<img width="727" alt="image"
src="https://github.com/user-attachments/assets/1f4d2938-eda0-4bb0-b6e5-2532cf8e0f8c"
/>

After:
<img width="395" alt="image"
src="https://github.com/user-attachments/assets/b7422bd9-2d9f-41d3-9963-69bf593cd7fa"
/>


## Types of changes
<!--- What types of changes does your code introduce? Put an `x` in all
the boxes that apply: -->
- [ ] 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)

Author: mrlacey

WinUIGallery/Samples/ControlPages/Accessibility/AccessibilityColorContrastPage.xaml

@@ -41,7 +41,7 @@
                 .<LineBreak />
                 <LineBreak />
                 To ensure optimal accessibility and usability, apps should strive to use high-contrast and easy-to-
-                read color combinationto for text and its background. Not only will this benefit users with lower
+                read color combinations for text and its background. Not only will this benefit users with lower
                 visual acuity, but this will also ensure visibility and legibility under a wide range of lighting
                 conditions, screens, and device settings.<LineBreak />
                 <LineBreak />