net, flat overlay: Mark tests

Flat overlay tests are not currently supported on IPv6
single-stack clusters, but they are still collected when
running tests on such clusters.
In this PR, these tests are marked for IPv4 and jumbo frame
accordingly.

Signed-off-by: Asia Khromov <azhivovk@redhat.com>

Author: azhivovk

tests/network/flat_overlay/test_flat_overlay.py

@@ -13,13 +13,13 @@
     pytest.mark.usefixtures(
         "enable_multi_network_policy_usage",
     ),
+    pytest.mark.ipv4,
 ]
 
 
 @pytest.mark.s390x
 class TestFlatOverlayConnectivity:
     @pytest.mark.gating
-    @pytest.mark.ipv4
     @pytest.mark.polarion("CNV-10158")
     # Not marked as `conformance`; requires NMState
     @pytest.mark.dependency(name="test_flat_overlay_basic_ping")
@@ -93,6 +93,7 @@ def test_flat_overlay_consistent_ip(
         )
 
 
+@pytest.mark.jumbo_frame
 class TestFlatOverlayJumboConnectivity:
     @pytest.mark.polarion("CNV-10162")
     @pytest.mark.s390x

tests/network/flat_overlay/test_multi_network_policy.py

@@ -5,10 +5,13 @@
 from tests.network.utils import assert_no_ping
 from utilities.network import assert_ping_successful
 
-pytestmark = pytest.mark.usefixtures(
-    "enable_multi_network_policy_usage",
-    "flat_l2_port",
-)
+pytestmark = [
+    pytest.mark.usefixtures(
+        "enable_multi_network_policy_usage",
+        "flat_l2_port",
+    ),
+    pytest.mark.ipv4,
+]
 
 
 @pytest.mark.polarion("CNV-10644")