internal/system: optional op check parallelism

The PipeWire Op check cannot be made parallel due to the OS interaction.

Signed-off-by: Ophestra <cat@gensokyo.uk>

internal/system/wayland_test.go

@@ -11,7 +11,7 @@ import (
 func TestWaylandOp(t *testing.T) {
 	t.Parallel()
 
-	checkOpBehaviour(t, []opBehaviourTestCase{
+	checkOpBehaviour(t, 0, []opBehaviourTestCase{
 		{"chmod", 0xbeef, 0xff, &waylandOp{nil,
 			m("/tmp/hakurei.1971/ebf083d1b175911782d413369b64ce7c/wayland"),
 			m("/run/user/1971/wayland-0"),