devel branch FTBFS since aufs-dkms 4.14 is in sid

The simplest fix is probably to upload the 4.13 aufs-dkms package to our custom APT repo until we’re ready to switch to 4.14 (#14976 (closed)).

Feature Branch: bugfix/15132-devel-ftbfs

Related issues

• Blocks #13245 (closed)
• Blocks #15052 (closed)
• Blocks #12460 (closed)
• Blocks #14521 (closed)
• Blocks #15029 (closed)
• Blocks #14580
• Blocks #15116
• Blocks #9059 (closed)

Original created by @intrigeri on 15132 (Redmine)