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

brightnessctl: added elogind build option
https://github.com/void-linux/void-packages/pull/38338

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

- This new package conforms to the [quality requirements](https://github.com/void-linux/void-packages/blob/master/Manual.md#quality-requirements): **YES**

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#### Local build testing
- I built this PR locally for my native architecture, (amd64-glibc)

This option allows brightnessctl to access backlight devices using the `(e)logind` api. First PR, and I wasn't sure if a revbump was necessary. If I need to change anything lmk.