[CI] Reduce Flakiness For test_spec_decode.py::test_suffix_decoding_acceptance (vllm-project#30367)

Signed-off-by: Micah Williamson <[email protected]>

Author: micah-wil

tests/v1/e2e/test_spec_decode.py

@@ -191,8 +191,8 @@ def test_suffix_decoding_acceptance(
     # Expect the acceptance rate to improve.
     assert first_accept_rate < last_accept_rate
 
-    # Heuristic: expect at least 82.5% acceptance rate at the end.
-    assert last_accept_rate > 0.825
+    # Heuristic: expect at least 80.0% acceptance rate at the end.
+    assert last_accept_rate > 0.80
 
     del spec_llm
     torch.cuda.empty_cache()