[FIX] point_of_sale: skip synchronize journal entries in PoS

The problem happens when the company is Angelo Saxon, and
`l10n_eg_edi_eta` is installed. Also, the product should have a cost and
automatic inventory valuation.
https://github.com/odoo/odoo/commit/4b430f8e30efb15f06982e4673cd73531a2119b3


The problem is that with this commit, after calling the
`_set_next_sequence` function, it calls `flush_recordset`. It would cause
a write to be triggered and add an Automatic Balancing Line. While in
`_create_account_move` of PoS the stock output line will add later to it,
and make it unbalanced. The first Automatic Balancing Line is incorrect as
it will call `_create_stock_output_lines` later and it adds a line which
makes it balance. But with that Automatic Balancing Line as it's
unbalanced at the end it will call `_close_session_action` in PoS and
shows a pop-up to add another line to make it balance.

The solution is skip synchronize of journal entries.

opw-3137723

closes odoo/odoo#110956

Signed-off-by: Trinh Jacky (trj) <trj@odoo.com>