remove sign in with apple feature flag logic from auth footer
remove sign in with apple feature flag logic from auth footer

- fix jsx-a11y/anchor-is-valid error by replacing Link with Clickable
- maintain the same style and behavior of clickable text

joeyAghion/force,joeyAghion/force,artsy/force,joeyAghion/force,artsy/force-public,artsy/force-public,artsy/force,joeyAghion/force,artsy/force,artsy/force