[IMP] report_xml: test performance improvement

- Create setUpClass method
- Include context keys for avoiding mail operations overhead.

report_xml/tests/test_report_xml.py

@@ -7,6 +7,20 @@ from odoo.tests import common
 
 
 class TestXmlReport(common.TransactionCase):
+    @classmethod
+    def setUpClass(cls):
+        super().setUpClass()
+        # Remove this variable in v16 and put instead:
+        # from odoo.addons.base.tests.common import DISABLED_MAIL_CONTEXT
+        DISABLED_MAIL_CONTEXT = {
+            "tracking_disable": True,
+            "mail_create_nolog": True,
+            "mail_create_nosubscribe": True,
+            "mail_notrack": True,
+            "no_reset_password": True,
+        }
+        cls.env = cls.env(context=dict(cls.env.context, **DISABLED_MAIL_CONTEXT))
+
     def test_xml(self):
         report_object = self.env["ir.actions.report"]
         report_name = "report_xml.demo_report_xml_view"