Description of problem:
pipewire is logging errors related to libspa-jack.so.

Version-Release number of selected component (if applicable):
pipewire-0.3.7-2.fc32.x86_64

How reproducible:
Always.

Steps to Reproduce:
1. systemctl --user start pipewire
2. journalctl --no-hostname --user -u pipewire -f

Actual results:
Jul 28 14:40:39 systemd[1561]: Started Multimedia Service.
Jul 28 14:40:39 pipewire[2141]: [E][000000027.127265][pipewire.c:118 open_plugin()] can't load /usr/lib64/spa-0.2/jack/libspa-jack.so: /usr/lib64/spa-0.2/jack/libspa-jack.so: cannot open shared object file: No such file or directory
Jul 28 14:40:39 pipewire[2141]: [E][000000027.127278][pipewire.c:254 pw_load_spa_handle()] can't load 'jack/libspa-jack': No such file or directory
Jul 28 14:40:39 pipewire[2141]: [E][000000027.127281][spa-device.c:144 pw_spa_device_load()] can't load device handle: No such file or directory
Jul 28 14:40:39 pipewire[2141]: [E][000000027.127285][module-device-factory.c:167 create_object()] can't create device: No such file or directory
Jul 28 14:40:39 pipewire[2141]: [E][000000027.127288][private.h:241 pw_core_resource_errorv()] resource 0x55b17df7c3b0: id:4 seq:4 res:-2 (No such file or directory) msg:"can't create device: No such file or directory"
Jul 28 14:40:39 pipewire[2156]: [E][000000027.127452][core.c:71 core_event_error()] core 0x55ce3d003e60: proxy 0x55ce3d01fea0 id:4: seq:4 res:-2 (No such file or directory) msg:"can't create device: No such file or directory"
Jul 28 14:40:39 pipewire[2156]: [E][000000027.127460][media-session.c:1743 core_error()] error id:4 seq:4 res:-2 (No such file or directory): can't create device: No such file or directory
Jul 28 14:40:39 pipewire[2141]: [E][000000027.133611][alsa-pcm.c:33 spa_alsa_open()] 'front:2': playback open failed: Device or resource busy
Jul 28 14:40:39 pipewire[2141]: [W][000000027.133625][adapter.c:175 find_format()] adapter 0x55b17df679c0: can't get format: Device or resource busy
Jul 28 14:40:39 pipewire[2141]: [E][000000027.133631][module-adapter.c:231 create_object()] can't create node: Device or resource busy
Jul 28 14:40:39 pipewire[2141]: [E][000000027.133636][private.h:241 pw_core_resource_errorv()] resource 0x55b17df7c3b0: id:44 seq:150 res:-16 (Device or resource busy) msg:"can't create node: Device or resource busy"
Jul 28 14:40:39 pipewire[2156]: [E][000000027.138927][core.c:71 core_event_error()] core 0x55ce3d003e60: proxy 0x55ce3d14fcb0 id:44: seq:150 res:-16 (Device or resource busy) msg:"can't create node: Device or resource busy"
Jul 28 14:40:39 pipewire[2156]: [E][000000027.138945][media-session.c:1743 core_error()] error id:44 seq:150 res:-16 (Device or resource busy): can't create node: Device or resource busy

Expected results:
No errors in the log.

Additional info:
pipewire-plugin-jack seems to provide the missing library, but it's not required or even recommended by pipewire{,-libs}.