Pre-built Images need internet connectivity on first power-up

[akuker]

Info

With the v23.04.01 (and earlier) releases, the Raspberry Pi needs to be connected to the internet in order to download several Python packages for the web interface.

There is logic in easyinstall.sh that tries to cache the packages, but it doesn't seem to be working properly.

[akuker]

PR #1148 tried to fix this, but it just downloaded the packages to the ~/piscsi/python/web directory.

Some observations:

• When using the pip3 install -r requirements.txt it appears that only the first package was actually cached.
• Some of the older versions of python required a pip conf file in the home directory. It looks like that's not supposed to be needed with newer versions of python.
• Note that the web interface is running as root, so the cached information is supposed to be in /root/.cache/

Pip cache commands:
https://pip.pypa.io/en/stable/cli/pip_cache/