[V0 Deprecation] Remove VLLM_USE_V1 from tests (#26341)

Signed-off-by: DarkLight1337 <tlleungac@connect.ust.hk>

tests/v1/entrypoints/llm/test_struct_output_generate.py

@@ -103,7 +103,6 @@ def test_guided_decoding_deprecated():
     PARAMS_MODELS_BACKENDS_TOKENIZER_MODE,
 )
 def test_structured_output(
-    monkeypatch: pytest.MonkeyPatch,
     sample_json_schema: dict[str, Any],
     unsupported_json_schema: dict[str, Any],
     sample_sql_ebnf: str,
@@ -115,8 +114,6 @@ def test_structured_output(
     model_name: str,
     speculative_config: dict[str, Any],
 ):
-    monkeypatch.setenv("VLLM_USE_V1", "1")
-
     if current_platform.is_tpu() and speculative_config:
         pytest.skip("TPU does not support speculative decoding")
 
@@ -620,15 +617,12 @@ Make the response as short as possible.
     ],
 )
 def test_structured_output_with_reasoning_matrices(
-    monkeypatch: pytest.MonkeyPatch,
     backend: str,
     tokenizer_mode: TokenizerMode,
     reasoning_parser: str,
     model_name: str,
     speculative_config: dict[str, Any] | None,
 ):
-    monkeypatch.setenv("VLLM_USE_V1", "1")
-
     if current_platform.is_tpu() and speculative_config:
         pytest.skip("TPU does not support speculative decoding")
 
@@ -691,13 +685,10 @@ def test_structured_output_with_reasoning_matrices(
 @pytest.mark.skip_global_cleanup
 @pytest.mark.parametrize("model_name, tokenizer_mode", PARAMS_MODELS_TOKENIZER_MODE)
 def test_structured_output_auto_mode(
-    monkeypatch: pytest.MonkeyPatch,
     unsupported_json_schema: dict[str, Any],
     model_name: str,
     tokenizer_mode: str,
 ):
-    monkeypatch.setenv("VLLM_USE_V1", "1")
-
     llm = LLM(
         model=model_name,
         max_model_len=1024,
@@ -739,9 +730,7 @@ def test_structured_output_auto_mode(
 
 
 @pytest.mark.skip_global_cleanup
-def test_guidance_no_additional_properties(monkeypatch: pytest.MonkeyPatch):
-    monkeypatch.setenv("VLLM_USE_V1", "1")
-
+def test_guidance_no_additional_properties():
     llm = LLM(
         model="Qwen/Qwen2.5-1.5B-Instruct",
         max_model_len=1024,
@@ -801,12 +790,9 @@ def test_guidance_no_additional_properties(monkeypatch: pytest.MonkeyPatch):
 
 @pytest.mark.parametrize("backend", ["guidance", "xgrammar", "outlines"])
 def test_structured_output_batched_with_non_structured_outputs_requests(
-    monkeypatch: pytest.MonkeyPatch,
     sample_json_schema: dict[str, Any],
     backend: str,
 ):
-    monkeypatch.setenv("VLLM_USE_V1", "1")
-
     # Don't use eager execution on TPUs because we want to test for no
     # recompilation at runtime
     enforce_eager = bool(not current_platform.is_tpu())