[Attention] Support distinguishing between short extends and decodes (#37303)

Signed-off-by: Lucas Wilkinson <lwilkins@redhat.com>

.buildkite/test_areas/engine.yaml

@@ -70,3 +70,15 @@ steps:
       device: mi325_4
       depends_on:
       - image-build-amd
+
+- label: V1 e2e (4xH100)
+  timeout_in_minutes: 60
+  device: h100
+  num_devices: 4
+  optional: true
+  source_file_dependencies:
+    - vllm/v1/attention/backends/utils.py
+    - vllm/v1/worker/gpu_model_runner.py
+    - tests/v1/e2e/test_hybrid_chunked_prefill.py
+  commands:
+    - pytest -v -s v1/e2e/test_hybrid_chunked_prefill.py