Fix: provide correct paths for install shell

[m3talsmith]

Issue #, if available:

Description of Changes

When trying to get the project up and running to work on #624 , I noticed that the install script didn't work as documented. Delving deeper it was due to the compiled assets not being in the path the script expected. I fixed the paths in the script (not the build) so that they could copy assets from the build directories.

Additionally, I fix the python3.9 error that will popup if you have a version greater than python3.9.

Description of how you validated changes

I manually ran the install and unsinstall scripts until the install passed and I could use agc.

Checklist

• If this change would make any existing documentation invalid, I have included those updates within this PR
• I have added unit tests that prove my fix is effective or that my feature works
• I have linted my code before raising the PR
• Title of this Pull Request follows Conventional Commits standard: https://www.conventionalcommits.org/en/v1.0.0/

---

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license