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

vault: chown config dir to service user
https://github.com/void-linux/void-packages/pull/28200

Description:
Dunno why I missed this before, but:
```
$ sudo -u _vault vault server -config=/etc/vault
Password:
error loading configuration from /etc/vault: open /etc/vault: permission denied
$ sudo chown _vault:_vault /etc/vault
$ sudo -u _vault vault server -config=/etc/vault
==> Vault server configuration:
<...>
```