Skip test_bgp_multipath_relax.py on t1-isolated (sonic-net#18558)

Description of PR
Summary: Skip bgp/test_bgp_multipath_relax.py on t1-isolated topologies.
Skip because the test is not designed for t1-isolated and it fails.

Signed-off-by: Guy Shemesh <[email protected]>

Author: justin-wong-ce

tests/common/plugins/conditional_mark/tests_mark_conditions.yaml

@@ -160,8 +160,10 @@ bgp/test_bgp_gr_helper.py:
 bgp/test_bgp_multipath_relax.py:
   skip:
     reason: "Not supported topology backend."
+    conditions_logical_operator: or
     conditions:
       - "'backend' in topo_name"
+      - "'t1-isolated' in topo_name"
 
 bgp/test_bgp_port_disable.py:
   skip: