FlashList optional dependency (#2559)

* FlashList optional dependecy

* Update src/optionalDependencies/index.web.ts

Co-authored-by: Lidor Dafna <66782556+lidord-wix@users.noreply.github.com>

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Co-authored-by: Lidor Dafna <66782556+lidord-wix@users.noreply.github.com>

Author: adids1221

src/optionalDependencies/index.web.ts

@@ -4,4 +4,5 @@ export {default as SvgPackage} from './SvgPackage';
 export {createShimmerPlaceholder} from './ShimmerPackage';
 export {default as LinearGradientPackage} from './LinearGradientPackage';
 export {default as PostCssPackage} from './PostCssPackage';
+export {default as FlashListPackage} from './FlashListPackage';