Add setup-python to publishing workflow

[thomas-bc]

Related Issue(s)
Has Unit Tests (y/n)
Documentation Included (y/n)

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Change Description

Fixes the infamous Python3.12 error on the new ubuntu-24 runners

error: externally-managed-environment

× This environment is externally managed
╰─> To install Python packages system-wide, try apt install
    python3-xyz, where xyz is the package you are trying to
    install.
    
    If you wish to install a non-Debian-packaged Python package,
    create a virtual environment using python3 -m venv path/to/venv.
    Then use path/to/venv/bin/python and path/to/venv/bin/pip. Make
    sure you have python3-full installed.
    
    If you wish to install a non-Debian packaged Python application,
    it may be easiest to use pipx install xyz, which will manage a
    virtual environment for you. Make sure you have pipx installed.
    
    See /usr/share/doc/python3.[12](https://github.com/nasa/fprime-gds/actions/runs/11337276200/job/31528619309#step:4:13)/README.venv for more information.