Disable interactive mode in CI

https://github.com/ligurio/unreliablefs/runs/5972280248

Setting up libsasl2-modules-db:amd64 (2.1.27+dfsg-2ubuntu1) ...
Setting up tzdata (2021e-0ubuntu0.21.04) ...
debconf: unable to initialize frontend: Dialog
debconf: (No usable dialog-like program is installed, so the dialog based frontend cannot be used. at /usr/share/perl5/Debconf/FrontEnd/Dialog.pm line 76.)
debconf: falling back to frontend: Readline
Configuring tzdata
------------------

Please select the geographic area in which you live. Subsequent configuration
questions will narrow this down by presenting a list of cities, representing
the time zones in which they are located.

  1. Africa   3. Antarctica  5. Arctic  7. Atlantic  9. Indian    11. US
  2. America  4. Australia   6. Asia    8. Europe    10. Pacific  12. Etc
�[4mGeographic area: �[24m�[1m
Timed out!

ligurio / unreliablefs

Disable interactive mode in CI #108