fix: update the airgap scripts to work with 1.8

[NohaIhab]

Description

Some changes to the airgapped script to use it for testing CKF 1.8 part of #889

Summary

• use sudo to run microk8s commands, this is needed for strict microk8s
• pin requests dependency version until docker issue is resolved
• use sudo with juju bootstrap microk8s for strict microk8s
• install python3-pip before running pip3 install
• remove unrecognized arguments for save-charms-to-tar.py

[kimwnasptd]

Let's ignore my message above for now. It looks like this happens on specific versions of pip.

If this happens users can create a virtual environment.

LGTM