frome: Add a dependency on python3-apt

python3-debian only recommends to to install python3-apt but does not depend on it.

Forcing installation.

https://phabricator.apertis.org/T8629

test-cases/frome.yaml

@@ -29,6 +29,7 @@ install:
     - frome-tests
     - gnome-desktop-testing
     - python3-debian
+    - python3-apt
   steps:
     # Download in /tmp directory
     - cd /tmp/