The solution used by Linux Mint seems apt: cd /etc/apt/preferences.d/ cat nosnap...

The solution used by Linux Mint seems apt:

    cd /etc/apt/preferences.d/
    cat nosnap.pref
    # To prevent repository packages from triggering the installation of Snap,
    # this file forbids snapd from being installed by APT.
    # For more information: https://linuxmint-user-guide.readthedocs.io/en/latest/snap.html

    Package: snapd
    Pin: release a=*
    Pin-Priority: -10