[FIX] test_impex: cursor cache in tests

As the same cursor is used by all tests, make sure to clear its `cache`
upon setup.

odoo/addons/test_impex/tests/test_load.py

@@ -40,6 +40,7 @@ class ImporterCase(common.TransactionCase):
         super(ImporterCase, self).setUp()
         self.model = self.env[self.model_name]
         self.env['ir.model.data'].clear_caches()
+        self.cr.cache.clear()
 
     def import_(self, fields, rows, context=None):
         return self.model.with_context(context or {}).load(fields, rows)