test: pin HELP_TOKENS_VERSION in instructor-dashboard SUPPORT_URL tests

The asserted help-tokens URL includes the doc version, which varies
between master ("latest") and release branches ("open-release-<name>.master"),
causing the tests to fail on release branches. Pin HELP_TOKENS_VERSION
to "latest" so the tests are deterministic regardless of which branch
they run on.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: brian-smith-tcril

lms/djangoapps/mfe_config_api/tests/test_views.py

@@ -297,6 +297,7 @@ def side_effect(key, default=None):
         # Value in original MFE_CONFIG not overridden by catalog config should be preserved
         self.assertEqual(data["PRESERVED_SETTING"], "preserved")  # noqa: PT009
 
+    @override_settings(HELP_TOKENS_VERSION="latest")
     @patch("lms.djangoapps.mfe_config_api.views.configuration_helpers")
     def test_legacy_overrides_instructor_dashboard(self, configuration_helpers_mock):
         """Legacy help-tokens SUPPORT_URL is included for instructor-dashboard when no explicit override is set."""
@@ -769,6 +770,7 @@ def side_effect(key, default=None):
         brand_new = apps_by_id["org.openedx.frontend.app.brand.new"]["config"]
         self.assertEqual(brand_new["BRAND_NEW_KEY"], "value")  # noqa: PT009
 
+    @override_settings(HELP_TOKENS_VERSION="latest")
     @patch("lms.djangoapps.mfe_config_api.views.configuration_helpers")
     def test_legacy_overrides_instructor_dashboard_support_url(self, configuration_helpers_mock):
         """Instructor dashboard gets SUPPORT_URL from help-tokens when no explicit override is set."""