Do not show successfully verified page

What does this MR do and why?

When the following sequence of actions happens:

• the identity_verification FF is turned on
• an account is created and identity verification is not completed
• someone logs into GitLab with another account in the same browser

Then the Verification successful page is shown when it should not be shown. This MR fixes that.

Issue: #384163 (closed)

Screenshots or screen recordings

Screen_Recording_2022-12-14_at_13.34.10

How to set up and validate locally

1. In rails console enable the identity_verification feature flag

   Feature.enable(:identity_verification)

2. Log out of your local instance and create a new account
3. Do not finish verification
4. visit http://localhost:3000/users/sign_in and login with an existing account

MR acceptance checklist

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• I have evaluated the MR acceptance checklist for this MR.