ActiveRecord SQLite3 >= 6.0 represents boolean values as integers by default, leads to errors after upgrade

Expected Behavior

Mail should be delivered.

Actual Behavior

I recently updated our schleuder instance from 3.4 to 3.6. After that mail delivery to schleuder fails with the following error message:

List has no admins configured, cannot run! (In `/var/lib/schleuder/lists/foo/bar`.)

Every list has one or more configured admin addresses.

Steps to Reproduce the Problem

1. Upgrade Debian version from Buster to Bullseye
2. Send a mail to an already exisiting and working mailing list
3. With for an error mail

Specifications

• Version: 3.6
• Installation method: Debian Bullseye package

Other information

Manual re-enabling every admin address works:

schleuder-cli subscriptions set foo@bar.org admin false
schleuder-cli subscriptions set foo@bar.org admin true