The main goal of this commit is to reduce the size of the registry by
removing the (almost) useless __last_update field.
Statistics # of fields with all modules installed:
before 30184 fields, 1299x last_update (4.30%)
Before this commit, the computed field __last_update was added on every model.
The idea behind this field was to have a computed field that had either
the write_date or the create_date if the write_date was empty. However,
the write_date is always written, even on creation, making it useless
to have the computed field __last_update
After this update, we completely remove from BaseModel:
* __last_update
* CONCURRENCY_CHECK_FIELD that was always defined as "__last_update"
* _compute_concurrency_field that was the compute function for __last_update
closesodoo/odoo#105739
Task-id: 3062140 (part of 3062137 improve registry load time)
Related: odoo/upgrade#4038
Related: odoo/enterprise#33939
Signed-off-by: Raphael Collet <rco@odoo.com>