Following the removal of explicit view configuration fields and
the `_compute_view_configuration_fields` method in the payment
module, this commit updates the documentation accordingly. It
removes all references and instructions related to
`_compute_view_configuration_fields`, ensuring the documentation
reflects the current implementation that leverages XPath for
view customization.
task-3679393
See odoo/odoo#152517
See odoo/enterprise#56181
See odoo/upgrade#5667closesodoo/documentation#7686
Signed-off-by: Antoine Vandevenne (anv) <anv@odoo.com>