web/web_duplicate_visibility/demo/res_users_view.xml

<?xml version="1.0" encoding="UTF-8"?>
<odoo>
     <record id="view_users_form" model="ir.ui.view">
        <field name="inherit_id" ref="base.view_users_form"/>
        <field name="model">res.users</field>
        <field name="arch" type="xml">
            <xpath expr="//form" position="attributes">
                <attribute name="duplicate">0</attribute>
            </xpath>
        </field>
     </record>
</odoo>