bpo-43319: Fixed the tutorial on venv about standard library (GH-24740)

In the [official tutorial on virtual environment](https://docs.python.org/3/tutorial/venv.html#creating-virtual-environments)

> This will create the tutorial-env directory if it doesn’t exist, and also create directories inside it containing a copy of the Python interpreter, **the standard library**, and various supporting files.

According to the actual behavior of `venv` and [PEP 405](https://www.python.org/dev/peps/pep-0405/#id15)'s description about virtual environment, no standard library file is included in the virtual environment's directory.

Automerge-Triggered-By: GH:vsajip