[FIX] website_sale: delete child category on parent
[FIX] website_sale: delete child category on parent

In the case of deletion with `ondelete="set null"`, return_path of
children of deleted record will not have return_path updated.

So remove the children recursively.

Another fix was done in 13.0 to avoid most issue in 6d5cd8b1d19.

opw-2148046
closes #41075

closes odoo/odoo#41178

X-original-commit: 6d5cd8b1d194fb173c486355c89d2ce503fd0ba4
Signed-off-by: Nicolas Lempereur (nle) <2907e499a003d1c3ab7944c0a40c6df46e3e3c2f@odoo.com>

ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo