Add number | null to ViewProps['hitSlop'] TypeScript type (#41070)

Summary:
Setting the `hitSlop` of a `View` to be a `number` didn't work. The Flow type already allows `number`:
https://github.com/facebook/react-native/blob/6e42c98aa3423cfbc389e4fe877b5c6b559c8a81/packages/react-native/Libraries/Components/View/ViewPropTypes.js#L618

 I updated it to match the [`TouchableWithoutFeedbackProps['hitSlop']`](https://github.com/facebook/react-native/blob/6e42c98aa3423cfbc389e4fe877b5c6b559c8a81/packages/react-native/Libraries/Components/Touchable/TouchableWithoutFeedback.d.ts#L72) and [`PressableProps['hitSlop']`](https://github.com/facebook/react-native/blob/6e42c98aa3423cfbc389e4fe877b5c6b559c8a81/packages/react-native/Libraries/Components/Pressable/Pressable.d.ts#L126) types.

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[GENERAL] [FIXED] Add `number | null` to `ViewProps['hitSlop']` TypeScript type

Pull Request resolved: #41070

Test Plan: Ran `yarn test-typescript` and `yarn test-typescript-offline` and there were no errors.

Reviewed By: rshest

Differential Revision: D50451318

Pulled By: javache

fbshipit-source-id: a0fceba270dbb80383cceb16f7719252a05b62b5

Author: DimitarNestorov

packages/react-native/Libraries/Components/View/ViewPropTypes.d.ts

@@ -184,7 +184,7 @@ export interface ViewProps
    * the Z-index of sibling views always takes precedence if a touch
    * hits two overlapping views.
    */
-  hitSlop?: Insets | undefined;
+  hitSlop?: null | Insets | number | undefined;
 
   /**
    * Used to reference react managed views from native code.