Add ruff, remove black, isort, flake8, pylint (#3092)

* black, isort, flake8 -> ruff

* remove unused

* add back needed import

* fix

tests/e2e/multigpu/solo/test_flex.py

@@ -31,7 +31,6 @@ class TestPackedFlex:
 
     @require_torch_2_6_0
     def test_loss_llama(self, temp_dir):
-        # pylint: disable=duplicate-code
         cfg = DictDefault(
             {
                 "base_model": "HuggingFaceTB/SmolLM2-135M",

tests/e2e/multigpu/solo/test_grpo.py

@@ -80,7 +80,7 @@ def start_vllm(
     cmd_env = env.copy()
     cmd_env.update({"VLLM_LOGGING_CONFIG_PATH": vllm_logging_json})
     # start `trl vllm-serve` command in the background and capture the process id
-    process = subprocess.Popen(  # pylint: disable=consider-using-with
+    process = subprocess.Popen(
         cmd,
         env=cmd_env,
         stdout=subprocess.DEVNULL if quiet else subprocess.PIPE,