commit [1] addeed production cost account. However this account is
mandatory with real time valuation. It could be an issue during
production because we don't have an automatic way to create a new
valid account. On top of it this behavior is optional and people
could still use the classical input and output account for production.
This commit make the cost of production account optional and fallback
on previous behavior with input/output accounts
[1] commit 1eb2e7c814closesodoo/odoo#136463
X-original-commit: ea647812e76931f9193ae841f428b312b861739b
Signed-off-by: William Henrotin (whe) <whe@odoo.com>