[UT] Add new ut case for aclgraph in auto enable

[lilinsiman]

What this PR does / why we need it?

add new ut case for aclgraph in auto enable

Does this PR introduce any user-facing change?

no

How was this patch tested?

ut

• vLLM version: v0.11.0
• vLLM main: vllm-project/vllm@83f478b

[github-actions]

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[gemini-code-assist]

Code Review

This pull request adds a new unit test to verify the behavior of aclgraph auto-enabling. The test case is relevant and covers an important configuration path. My review includes one suggestion to improve the robustness of the test by making the log assertion less fragile, which will improve its long-term maintainability.

[gemini-code-assist]

Checking for a log message at a specific index cm.output[1] makes the test fragile. If other log messages are added or their order changes in the future, this test will break unexpectedly. It's more robust to check if the expected message exists anywhere in the log output, rather than relying on its exact position.

Suggested change

	self.assertTrue(
	"PIECEWISE compilation enabled on NPU. use_inductor not supported - "
	"using only ACL Graph mode" in
	cm.output[1])
	self.assertTrue(any(
	"PIECEWISE compilation enabled on NPU. use_inductor not supported - "
	"using only ACL Graph mode" in message
	for message in cm.output), "Expected log message not found.")