[FIX] account: Keep CABA tax account when reversing

When reversing the CABA entry, the CABA tax account was replaced by the transition tax account if not set on the repartition line.
To reproduce:
Set up a CABA tax with ACC1 as transition tax account and ACC2 as tax account.
When creating the CABA entry, there is a line on ACC1 and another on ACC2.
When reversing the CABA entry, both lines are now on ACC1.

Introduced by https://github.com/odoo/odoo/pull/79556



closes odoo/odoo#81986

Issue: 2718413
X-original-commit: d22cd547
Signed-off-by: Laurent Smet <las@odoo.com>