DLPX-93224 Remove unnecessary tasks related to python3.11 added by previous os-upgrade PRs

[palash-gandhi]

Problem

In my previous PRs on this branch, I added python3.11 as a dependency in the bootstrap role.
Prakash pointed out that this was not required since it is already listed as a build dependency of
the virtualization package and will be installed at build time. As such, I am undoing my previous changes
around python3.11 and the associated PPA.
Prakash also pointed out that unattended-upgrades should be stopped and removed before we install
any packages.

This PR also addresses some other bugs found during testing using the resulting DE-based buildserver:

1. appliance-build fails in this task while trying to hash a password. Apparently, ansible needs passlib to be installed. I tried installing it directly in the role but ansible still could not find the module. I tried installing it in the chroot env via apt and also via pip, none of those worked. I finally resorted to installing it via bootstrap.
2. appliance-build fails when trying to run aws commands because it's not available in the path. It was found that snapd is not installed on DE-based buildservers and is in fact installed via a dependency by the bootstrap role. The bootstrap role then goes on to install aws-cli via snap but the Jenkins job continues to use the same shell which is why the path is not updated. When I tried to update the path and run the job, I realized that snap didn't allow the aws command to run because the home directory on a DE-based buildserver is not in /home:

delphix@ip-10-110-219-152:~$ aws
Sorry, home directories outside of /home needs configuration.
See https://forum.snapcraft.io/t/11209 for details.

I finally resorted to installing awscli via pip, system-wide.

Testing Done

https://ops-jenkins.eng-tools-prd.aws.delphixcloud.com/job/appliance-build/job/os-upgrade/job/pre-push/137/console

[prakashsurya]

LGTM, thanks.