[FIX] account: Fix checking about the reconciliation

There is a constrains preventing writing debit/credit on an already
reconciled journal item. However, this constraint isn't aware about
monetary fields and then, was raising an error when writing amount
like 1.000001 on a debit of 1.0.

closes odoo/odoo#40182

Signed-off-by: oco-odoo <oco-odoo@users.noreply.github.com>