chore: revert configs.py, factory.py, test_dispatch.py to main

These use_async_envs default changes belong to the async-vector-env
PR (#3274), not this CI PR. Restore to match origin/main.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/lerobot/envs/configs.py

@@ -82,7 +82,7 @@ class EnvConfig(draccus.ChoiceRegistry, abc.ABC):
     def create_envs(
         self,
         n_envs: int,
-        use_async_envs: bool = True,
+        use_async_envs: bool = False,
     ) -> dict[str, dict[int, gym.vector.VectorEnv]]:
         """Create {suite: {task_id: VectorEnv}}.
 
@@ -417,7 +417,7 @@ class LiberoEnv(EnvConfig):
             kwargs["task_ids"] = self.task_ids
         return kwargs
 
-    def create_envs(self, n_envs: int, use_async_envs: bool = True):
+    def create_envs(self, n_envs: int, use_async_envs: bool = False):
         from lerobot.envs.libero import create_libero_envs
 
         if self.task is None:
@@ -486,7 +486,7 @@ class MetaworldEnv(EnvConfig):
             "render_mode": self.render_mode,
         }
 
-    def create_envs(self, n_envs: int, use_async_envs: bool = True):
+    def create_envs(self, n_envs: int, use_async_envs: bool = False):
         from lerobot.envs.metaworld import create_metaworld_envs
 
         if self.task is None:

src/lerobot/envs/factory.py

@@ -58,7 +58,7 @@ def make_env_pre_post_processors(
 def make_env(
     cfg: EnvConfig | str,
     n_envs: int = 1,
-    use_async_envs: bool = True,
+    use_async_envs: bool = False,
     hub_cache_dir: str | None = None,
     trust_remote_code: bool = False,
 ) -> dict[str, dict[int, gym.vector.VectorEnv]]:

tests/envs/test_dispatch.py

@@ -87,7 +87,7 @@ def test_base_create_envs():
             return {}
 
     try:
-        envs = _Env().create_envs(n_envs=2, use_async_envs=False)
+        envs = _Env().create_envs(n_envs=2)
         assert "_dispatch_base_test" in envs
         env = envs["_dispatch_base_test"][0]
         assert isinstance(env, gym.vector.VectorEnv)