Supabase Auth - 'unauthorized_scope_error' for LinkedIn.

## The fix

Sign in with LinkedIn failing with unauthorized_scope_error: LinkedIn deprecated the old OAuth method. Fix: switch your Supabase project's LinkedIn provider configuration to the new LinkedIn OIDC provider, which is in production. The OIDC provider replaces the deprecated method and the error goes away. Maintainer-confirmed.

Thread: gh:supabase/auth#1216