There's a merged pull request on the void-packages repository

common/travis/xpkgdiff.sh: use newly-added arguments
https://github.com/void-linux/void-packages/pull/39093

Description:
it works without this, but it uses repo-default by default, so this should maybe speed some things up.

see also leahneukirchen/xtools#261

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#### Testing the changes
- I tested the changes in this PR: **YES**