Create new files for Apt repo configuration
Create new files for Apt repo configuration

Overwriting libfixposix-specific files in
/etc/apt/{preferences,sources.list}.d makes running the script
idempotent and suitable for users' machines instead of just the CI
environment.

attila-lendvai/iolib,sionescu/iolib,attila-lendvai/iolib,attila-lendvai/iolib,sionescu/iolib,sionescu/iolib