upgrade-manifest-old-data-keys (U1919)

The manifest lists files under update_xml or demo_xml, ignored since Odoo 19.0.

Applies to Odoo 19.0 and later.

What it does

Reports the manifest keys update_xml and demo_xml.

Why is this bad?

Odoo 19.0 only loads data and demo (and init_xml, which 20.0 ignores too): the files under the old keys are silently never loaded. Move them to data and demo.