[Thread] Disable flaky test nat64_withAilNat64Prefix_threadDevicePingIpv4InfraDevice_outboundPacketIsForwarded

Bug: 376573921
Change-Id: I017a7c3bfbb46a367a32156159495930120adb35
diff --git a/thread/tests/integration/src/android/net/thread/BorderRoutingTest.java b/thread/tests/integration/src/android/net/thread/BorderRoutingTest.java
index f6dd6b9..1a2ff06 100644
--- a/thread/tests/integration/src/android/net/thread/BorderRoutingTest.java
+++ b/thread/tests/integration/src/android/net/thread/BorderRoutingTest.java
@@ -74,6 +74,7 @@
 
 import org.junit.After;
 import org.junit.Before;
+import org.junit.Ignore;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -672,6 +673,7 @@
         }
     }
 
+    @Ignore("TODO: b/376573921 - Enable when it's not flaky at all")
     @Test
     public void nat64_withAilNat64Prefix_threadDevicePingIpv4InfraDevice_outboundPacketIsForwarded()
             throws Exception {