Log Message:
py-diffoscope: update to version 268

Changelog:

Version 268 includes the following changes:

[ Chris Lamb ]
* Drop apktool from Build-Depends; we can still test our APK code
via autopkgtests. (Closes: #1071410)
* Fix tests for 7zip version 24.05.
* Add a versioned dependency for at least version 5.4.5 for the xz
tests; they fail under (at least xz 5.2.8).
(Closes: reproducible-builds/diffoscope#374)

[ Vagrant Cascadian ]
* Relax Chris' versioned xz test dependency (5.4.5) to also allow
version 5.4.1.

Version 267 includes the following changes:

[ Chris Lamb ]
* Include "xz --verbose --verbose" (ie. double --verbose) output, not just
the single --verbose. (Closes: #1069329)
* Only include "xz --list" output if the xz has no other differences.