Provides a dummy ubuntu-system-adjustments package so Linux Mint
firefox will install on Ubuntu (or Debian).
Places nosnap.pref in /etc/apt/preferences.d/.
See: https://wjd.nu/notes/2022#ubuntu-snap-mint-chromium
dpkg-buildpackage -us -uc dpkg -i ../nosnap_0.1_all.deb apt-get install firefox