Standalone - prevent users from deleting own user

[wmortada]

Overview

Prevent users from deleting their own account.

Before

User can delete their own user account.

After

User unable to delete their own user account.

Comments

See also #28451 which is similar.

This won't stop admin users from deleting their own user until #28445 is merged but it will stop users with other roles from deleting their own user.

[civibot]

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[wmortada]

@artfulrobot

[artfulrobot]

I've r-run this and it works.