Why:
* Special:PasswordReset allows users to send an email containing
a temporary password to the email address attached to an account.
* Temporary accounts do not have passwords and cannot have an email
address set (as they cannot access Special:Preferences).
* Therefore, Special:PasswordReset does not provide holders of
temporary accounts a way to get access back into the temporary
account if they loose access.
* However, the form currently accepts temporary account usernames
and we should update the functionality to reject such usernames.
What:
* Update SpecialPasswordReset to reject temporary account usernames.
* Expand tests for SpecialPasswordReset to check this fix has worked.
Bug: T380085
Change-Id: I004453d4d16cd2a0448ac3922e4d13c24a158c8d
(cherry picked from commit e27be818690820c0df227cb06206da499eb94d38)
