[Attention] Update tests to remove deprecated env vars (#30563)

Signed-off-by: Matthew Bonanni <mbonanni@redhat.com>

tests/v1/spec_decode/test_eagle.py

@@ -15,6 +15,7 @@ from tests.v1.attention.utils import (
 )
 from vllm.attention.backends.registry import AttentionBackendEnum
 from vllm.config import (
+    AttentionConfig,
     CacheConfig,
     DeviceConfig,
     ModelConfig,
@@ -38,6 +39,7 @@ eagle3_dir = "yuhuili/EAGLE3-LLaMA3.1-Instruct-8B"
 def _create_proposer(
     method: str,
     num_speculative_tokens: int,
+    attention_backend: str | None = None,
     speculative_token_tree: list[tuple[int, ...]] | None = None,
 ) -> EagleProposer:
     model_config = ModelConfig(model=model_dir, runner="generate", max_model_len=100)
@@ -70,6 +72,7 @@ def _create_proposer(
             max_model_len=model_config.max_model_len,
             is_encoder_decoder=model_config.is_encoder_decoder,
         ),
+        attention_config=AttentionConfig(backend=attention_backend),
     )
 
     return EagleProposer(vllm_config=vllm_config, device=current_platform.device_type)
@@ -331,8 +334,6 @@ def test_load_model(
     use_distinct_lm_head,
     monkeypatch,
 ):
-    monkeypatch.setenv("VLLM_ATTENTION_BACKEND", attn_backend)
-
     if attn_backend == "TRITON_ATTN" and not current_platform.is_rocm():
         pytest.skip(
             "TRITON_ATTN does not support "
@@ -394,7 +395,9 @@ def test_load_model(
     assert not isinstance(target_model, SupportsMultiModal)
 
     # Create proposer using the helper function
-    proposer = _create_proposer(method, num_speculative_tokens=8)
+    proposer = _create_proposer(
+        method, num_speculative_tokens=8, attention_backend=attn_backend
+    )
 
     # Call the method under test
     proposer.load_model(target_model)
@@ -420,8 +423,6 @@ def test_load_model(
 @pytest.mark.parametrize("attn_backend", get_attn_backend_list_based_on_platform())
 @pytest.mark.parametrize("num_speculative_tokens", [1, 3, 8])
 def test_propose(method, attn_backend, num_speculative_tokens, monkeypatch):
-    monkeypatch.setenv("VLLM_ATTENTION_BACKEND", attn_backend)
-
     if attn_backend == "TRITON_ATTN" and not current_platform.is_rocm():
         pytest.skip(
             "TRITON_ATTN does not support "
@@ -449,7 +450,9 @@ def test_propose(method, attn_backend, num_speculative_tokens, monkeypatch):
     seq_lens = [seq_len_1, seq_len_2]
 
     # Create proposer first so we can use its actual hidden_size
-    proposer = _create_proposer("eagle", num_speculative_tokens)
+    proposer = _create_proposer(
+        "eagle", num_speculative_tokens, attention_backend=attn_backend
+    )
     # Get the hidden_size from the proposer to ensure consistency
     hidden_size = proposer.hidden_size
 
@@ -622,7 +625,9 @@ def test_propose_tree(spec_token_tree):
 
     # Create proposer first so we can use its actual hidden_size.
     proposer = _create_proposer(
-        "eagle", num_speculative_tokens, speculative_token_tree=spec_token_tree
+        "eagle",
+        num_speculative_tokens,
+        speculative_token_tree=spec_token_tree,
     )
     # Get the hidden_size from the proposer to ensure consistency.
     hidden_size = proposer.hidden_size