add userSelect to TextStyles attributes (#39024)

Summary:
This PR addresses the missing userSelect style support in the TypeScript definitions. While support for userSelect was introduced in commit [fc42d5b](fc42d5b), the associated TypeScript definitions were overlooked. This oversight led to issue #39015. This PR rectifies that by updating the type definitions accordingly.

## Changelog:

[GENERAL] [FIXED] - Updated TypeScript definitions to include userSelect style support. Refer to commit [2e4d8b6](2e4d8b6) for the specific changes.

Pull Request resolved: #39024

Reviewed By: rozele

Differential Revision: D48412051

Pulled By: NickGerleman

fbshipit-source-id: 425fc011af9052c8c4bde98e8524b7784493c546

packages/react-native/Libraries/StyleSheet/StyleSheetTypes.d.ts

@@ -339,6 +339,7 @@ export interface TextStyle extends TextStyleIOS, TextStyleAndroid, ViewStyle {
   textShadowOffset?: {width: number; height: number} | undefined;
   textShadowRadius?: number | undefined;
   textTransform?: 'none' | 'capitalize' | 'uppercase' | 'lowercase' | undefined;
+  userSelect?: 'auto' | 'none' | 'text' | 'contain' | 'all' | undefined;
 }
 
 /**