The user needs to be signed in to call unlinkIdentity().
The user must have at least 2 identities in order to unlink an identity.
The identity to be unlinked must belong to the user.
Examples
Unlink an identity
// retrieve all identites linked to a user
let identities = try await supabase.auth.userIdentities()
// find the google identity
let googleIdentity = identities.first \{
$0.provider == .google
\}
// unlink the google identity
try await supabase.auth.unlinkIdentity(googleIdentity)