multimedia/pipewire: unbreak ALSA=on with default config

$ pw-play foo.wav
stream node 42 error: no target node available
remote error: id=2 seq:7 res:-2 (No such file or directory): no target node available

PR: 272004
Approved by: arrowd (maintainer)

(cherry picked from commit a7aaffb08b1688f28121d1f12e8012fd40bf75e7)