[FIX] api: do not prefetch new records.

New records (with a NewId) are not necessary in the cache, but should
not be prefetched.
This check has been omitted during optimisation in b0c08a6846.

opw-1843566
opw-1843636
opw-1843683
opw-1843548
opw-1843629
opw-1843657

Closes #24595

odoo/models.py

@@ -4776,6 +4776,9 @@ class BaseModel(MetaModel('DummyModel', (object,), {'_register': False})):
         recs = self.browse(self._prefetch[self._name])
         ids = [self.id]
         for record_id in self.env.cache.get_missing_ids(recs - self, field):
+            if not record_id:
+                # Do not prefetch `NewId`
+                continue
             ids.append(record_id)
             if limit and limit <= len(ids):
                 break