The PR #282377 made files/directories specified in
`environment.etc."pipewire<...>"` and `environment.etc."wireplumber<...>"`
conflict with existing configuration of the PipeWire NixOS module due to how
the `configPackages` options were implemented. This sadly wasn't easily
avoidable. As this can cause breakage for users moving from 23.11 to 24.05
though, assertions can help guide them to use `services.pipewire.extraConfig`
or `services.pipewire.configPackages` / `services.wireplumber.configPackages`
instead, fixing the breakage.
5f6dca8403