chore: turn landing page flag on (#5684)

Revert "chore: turn landing page flag off (#5679)"

This reverts commit 0176c744.

src/featureFlags/flags/landingPage.ts

-import { BaseVariant, FeatureFlag, useBaseFlag } from '../index'
+import { BaseVariant } from '../index'
 
 export function useLandingPageFlag(): BaseVariant {
-  return useBaseFlag(FeatureFlag.landingPage)
+  return BaseVariant.Enabled
 }
 
 export { BaseVariant as LandingPageVariant }