[CI] Skip Phi-MoE test due to old API util (#31632)

Signed-off-by: Andreas Karatzas <akaratza@amd.com>

tests/models/language/generation/test_phimoe.py

@@ -60,6 +60,19 @@ def test_phimoe_routing_function():
         assert torch.equal(topk_ids, ground_truth[test_id]["topk_ids"])
 
 
+# There is a known issue that triggers `AttributeError: 'DynamicCache'
+# object has no attribute 'seen_tokens'` when running:
+# `tests/models/language/generation/test_phimoe.py::test_models
+#   [5-64-bfloat16-microsoft/Phi-3.5-MoE-instruct]`
+# This issue is being investigated and tracked in:
+#   https://huggingface.co/microsoft/Phi-3.5-MoE-instruct/discussions/58
+# It is platform-agnostic. Therefore, we skip this test on all platforms for now.
+@pytest.mark.skip(
+    reason="Skipping due to known issue: "
+    "'DynamicCache' object has no attribute 'seen_tokens'. See: "
+    "https://huggingface.co/microsoft/Phi-3.5-MoE-instruct/discussions/58 "
+    "for details.",
+)
 @pytest.mark.skipif(
     condition=current_platform.is_cpu(),
     reason="This test takes a lot time to run on CPU, "