[FIX] point_of_sale: remove radio button widget

We don't want a radio to be able to select none of the options.

addons/point_of_sale/views/pos_payment_method_views.xml

@@ -20,7 +20,7 @@
                             <field name="company_id" readonly="1" groups="base.group_multi_company" />
                         </group>
                         <group>
-                            <field name="use_payment_terminal" attrs="{'invisible': [('hide_use_payment_terminal', '=', True)]}" widget="radio" />
+                            <field name="use_payment_terminal" attrs="{'invisible': [('hide_use_payment_terminal', '=', True)]}" />
                         </group>
                     </group>
                 </sheet>