[gentoo] fix pip install fail as root

[chusiang]

The gentoo don't allow use the root to run the pip install command.

Running pip as root is not advised. It can render important system tools like emerge useless.[1]

pip - Gentoo Wiki

Error message from Docker Hub.

https://hub.docker.com/r/chusiang/ansible-jupyter/builds/b6fgkggbrgrybkz5dfesgzs/

...
Step 6/15 : RUN pip install -U pip

 ---> Running in e803e1f60837

[91mERROR: (Gentoo) Please run pip with the --user option to avoid breaking python-exec
[0m
Removing intermediate container e803e1f60837

The command '/bin/sh -c pip install -U pip' returned a non-zero code: 1

[chusiang]

I see the official ansible package is latest, I will use the equery to install ansible, not pip.

app-admin/ansible – Gentoo Packages

[chusiang]

I remove the pip install ansible part, but the setup playbook have some pip install tasks. 😢