fix: Automatic installation when the dependent package does not exist

[soulteary]

in some purer python environments:

root@c3bd6b22d446:/# python
Python 3.9.9 (main, Dec 21 2021, 10:35:05) 
[GCC 8.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import milvus
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python3.9/site-packages/milvus/__init__.py", line 9, in <module>
    from importlib_resources import files
ModuleNotFoundError: No module named 'importlib_resources'