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

wireplumber: export $XDG_STATE_HOME to a persistent location
https://github.com/void-linux/void-packages/pull/36650

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

In #36416 I've exported HOME to `/var/run/pipewire` but that directory gets recreated every reboot, it was able to persist volume and other configurations when the service restarts but not across system reboots.

`wireplumber` stores the state configuration in `${XDG_STATE_HOME:-$HOME/.local/state}/wireplumber`. I recently also found, `pipewire-media-session` (the builtin media router) utilized `/var/lib/pipewire` as well to persist its state across reboot. So this simply changes the export to do the same.