Assessment Link can not sign-in with Email Enumeration Protect On

[KoWeiJAC]

How to reproduce

• Turn off the Firebase > Authentication > User Action > Email Enumeration Protection

- Use Assessment links to sign-in

Cause

The fetchSignInMethodsForEmail(auth, user.email) function is used to in sign-in verification,
if the Email Enumeration Protection is on, the function will return empty array, cause the sign-in verification failed.
https://cloud.google.com/identity-platform/docs/admin/email-enumeration-protection

Expected

Assessment link can sign-in with Email Enumeration Protect On

[drieJAC]

@warrensearle Do you know if we need to make this call to get the sign in methods?