[FIX] account: avoid useless account move synchronization

Account move synchronization has already taken place during the creation
of the moves. No need for this additional check during the
reconciliation itself.

This commit helps when a lot of move lines are being reconciled at once.
For instance, the duration of the reconciliation of a batch of about 700
payments on a large database took 20 minutes before this commit, and
takes about 4 minutes after this commit.

closes odoo/odoo#67408

Signed-off-by: Laurent Smet <smetl@users.noreply.github.com>