chore: ignore A/B network latency test on m6a/m7a instances

Network latency (ping) A/B tests on m6a.metal and m7a.metal-48xl
exhibit high variance, causing flaky failures. This is consistent
with the existing exclusion of network throughput tests on these
AMD instances.

Signed-off-by: Takahiro Itazuri <itazur@amazon.com>

Author: zulinx86

tools/ab_test.py

@@ -126,6 +126,11 @@ def format_with_reduced_unit(value, unit):
         "performance_test": "test_vsock_throughput",
         "mode": "g2h",
     },
+    # Network latency on m6a.metal / m7a.metal
+    *[
+        {"instance": instance, "performance_test": "test_network_latency"}
+        for instance in ["m6a.metal", "m7a.metal-48xl"]
+    ],
     # Network latencies on m8i.metal-{48,96}xl w/ 5.10 host
     *[
         {