[Chore] Separate out vllm.utils.importlib (#27022)

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

tests/utils_/test_utils.py

@@ -24,7 +24,6 @@ from vllm.transformers_utils.detokenizer_utils import convert_ids_list_to_tokens
 from vllm.utils import (
     FlexibleArgumentParser,
     MemorySnapshot,
-    PlaceholderModule,
     bind_kv_cache,
     common_broadcastable_dtype,
     current_stream,
@@ -475,46 +474,6 @@ def test_common_broadcastable_dtype(dtypes, expected_result):
     assert common_broadcastable_dtype(dtypes) == expected_result
 
 
-def test_placeholder_module_error_handling():
-    placeholder = PlaceholderModule("placeholder_1234")
-
-    def build_ctx():
-        return pytest.raises(ModuleNotFoundError, match="No module named")
-
-    with build_ctx():
-        int(placeholder)
-
-    with build_ctx():
-        placeholder()
-
-    with build_ctx():
-        _ = placeholder.some_attr
-
-    with build_ctx():
-        # Test conflict with internal __name attribute
-        _ = placeholder.name
-
-    # OK to print the placeholder or use it in a f-string
-    _ = repr(placeholder)
-    _ = str(placeholder)
-
-    # No error yet; only error when it is used downstream
-    placeholder_attr = placeholder.placeholder_attr("attr")
-
-    with build_ctx():
-        int(placeholder_attr)
-
-    with build_ctx():
-        placeholder_attr()
-
-    with build_ctx():
-        _ = placeholder_attr.some_attr
-
-    with build_ctx():
-        # Test conflict with internal __module attribute
-        _ = placeholder_attr.module
-
-
 def test_model_specification(
     parser_with_config, cli_config_file, cli_config_file_with_model
 ):