[IMP] core: remove useless mapped call when calling filtered with a str

The mapped call is supposed to populate the cache, but that's already
taking care of by prefetching. It ends up adding an overhead instead.

The perf improvement is more noticeable on large recordsets.
For example, on a database populated with 100k res.partner records.

Before:

.. code-block:: python

    partners = env["res.partner"].search([])
    partners.filtered("name")  # warm up
    timeit.timeit(lambda: partners.filtered("name"), number=10)
    # result: 7.15

After:

.. code-block:: python

    partners = env["res.partner"].search([])
    partners.filtered("name")  # warm up
    timeit.timeit(lambda: partners.filtered("name"), number=10)
    # result: 4.67

closes odoo/odoo#105350

Signed-off-by: Rémy Voet <ryv@odoo.com>

odoo/models.py

@@ -5382,8 +5382,6 @@ class BaseModel(metaclass=MetaModel):
         if isinstance(func, str):
             name = func
             func = lambda rec: any(rec.mapped(name))
-            # populate cache
-            self.mapped(name)
         return self.browse([rec.id for rec in self if func(rec)])
 
     def grouped(self, key):