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

common/travis: make check-install use new rootdir.
https://github.com/void-linux/void-packages/pull/43304

Description:
The CI has `base-chroot` installed, but sometimes this script would try to install `base-system,` causing conflicts. This PR fixes that issue by using a brand-new rootdir.

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#### Testing the changes
- I tested the changes in this PR: **NO**

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