move venv import from file level to class level to avoid import error… (#575)

* move venv import from file level to class level to avoid import error on windows

* pass lint check

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Co-authored-by: Zhicheng Zhang <zhangzhicheng.zzc@alibaba-inc.com>

modelscope/utils/plugins.py

@@ -9,7 +9,6 @@ import os
 import pkgutil
 import shutil
 import sys
-import venv
 from contextlib import contextmanager
 from fnmatch import fnmatch
 from pathlib import Path
@@ -1144,6 +1143,7 @@ class EnvsManager(object):
         cfg = read_config(model_dir)
         self.plugins = cfg.get('plugins', [])
         self.allow_remote = cfg.get('allow_remote', False)
+        import venv
         self.env_builder = venv.EnvBuilder(
             system_site_packages=True,
             clear=False,