OAuth link information remains after deleting a user, causes fatal exception

If a user is linked to any OAuth accounts, and then that user is deleted, the OAuth link associations for that user remains in the auth_provider_oauth_token_account_assoc table. If the user tries to log in again using OAuth, an exception with an AUTH_PROVIDER_OAUTH_ERROR_INVALID_ENTRY message is thrown.

Steps to reproduce:

1. Link a user using OAuth. A row is created in the oauth token account assoc table.
2. Delete that user.
3. Try to login as that user using OAuth.
4. Exception is thrown.