Remove the use of import within when

vendor/miniaudio/common_unix.odin

@@ -0,0 +1,17 @@
+//+build !windows
+package miniaudio
+
+import "core:sys/unix"
+
+thread :: unix.pthread_t
+mutex :: unix.pthread_mutex_t
+event :: struct {
+	value: u32,
+	lock: unix.pthread_mutex_t,
+	cond: unix.pthread_cond_t,
+}
+semaphore :: struct {
+	value: c.int,
+	lock: unix.pthread_mutex_t,
+	cond: unix.pthread_cond_t,
+}