[VS Test] Skip flaky tests (sonic-net#1875)

* Skip flaky test, under investigation

Author: prsunny

tests/test_buffer_traditional.py

@@ -68,6 +68,7 @@ def setup_teardown_test(self, dvs):
         finally:
             self.teardown()
 
+    @pytest.mark.skip(reason="Failing. Under investigation")
     def test_zero_cable_len_profile_update(self, dvs, setup_teardown_test):
         self.pg_name_map = setup_teardown_test
         orig_cable_len = None

tests/test_speed.py

@@ -1,11 +1,13 @@
 """test_speed.py verifies that speed is set on interfaces and buffer manager behavies correctly on speed change."""
+import pytest
 
 
 class TestSpeedSet:
     # FIXME: This value should probably not be hardcoded since the persistent container can
     # specify a dynamic number of ports now.
     NUM_PORTS = 32
 
+    @pytest.mark.skip(reason="Failing. Under investigation")
     def test_SpeedAndBufferSet(self, dvs, testlog):
         configured_speed_list = []
         speed_list = ["10000", "25000", "40000", "50000", "100000"]