[FIX] account: allow change account on tax line

Before this commit, in invoice/bill, when changing
the account of a tax line while having one of the invoice
lines with tax 0%, the tax line was not displayed anymore.

The cause of the issue is that in _recompute_dynamic_lines
method, when setting the tax repartition lines to
recompute, we did not filter the 0 tax. The consequence was
that we had a delta between expected and current taxes,
although the line of tax 0% was not displayed anyway.
By filtering the 0 tax, we have expected taxes == current taxes,
so we do not have delta anymore, therefore no tax line to recompute.

opw-2901833

closes odoo/odoo#97663

Signed-off-by: Florian Gilbert (flg) <flg@odoo.com>