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

mkinitcpio: add missing runtime dependency
https://github.com/void-linux/void-packages/pull/43778

Description:
Because this error shows up when generating a new initramfs:
```
/usr/lib/initcpio/functions: line 1030: zstd: command not found
```

#### Testing the changes
- I tested the changes in this PR: **NO** (N/A?)

#### Local build testing
- I built this PR locally for my native architecture, (**x86_64**)