feat: enable forced mgmt route test on T2 (sonic-net#17210)

Description of PR
Enable route/test_forced_mgmt_route.py::test_update_forced_mgmt test case on T2 topo to resolve the T2 test gap.

Summary:
Fixes # (issue) Microsoft ADO 28837282

Approach
What is the motivation for this PR?
We want to run more tests on T2 topo to increase the test coverage. In this PR, we enabled route/test_forced_mgmt_route.py::test_update_forced_mgmt on T2 topo.

The other test case test_forced_mgmt_route_add_and_remove_by_mgmt_port_status() will still be skipped for multi-asic devices (for example, T2 devices) as I couldn't find a device with eth1 port available, so I never got the chance to verify it. I have created a GitHub issue here to track this: sonic-net#17250

How did you do it?
How did you verify/test it?
Elastictest link: https://elastictest.org/scheduler/testplan/67bf90c1fdc60a30648c223b?testcase=route%2Ftest_forced_mgmt_route.py&type=console&leftSideViewMode=detail

co-authorized by: jianquanye@microsoft.com

Author: cyw233

tests/route/test_forced_mgmt_route.py

@@ -11,7 +11,7 @@
 
 pytestmark = [
     pytest.mark.disable_loganalyzer,
-    pytest.mark.topology('t0'),
+    pytest.mark.topology('t0', 't2'),
     pytest.mark.device_type('vs')
 ]