Remove sc_queue

All uses have been replaced by VecDeque.

app/tests/test_queue.c

@@ -1,43 +0,0 @@
-#include "common.h"
-
-#include <assert.h>
-
-#include "util/queue.h"
-
-struct foo {
-    int value;
-    struct foo *next;
-};
-
-static void test_queue(void) {
-    struct my_queue SC_QUEUE(struct foo) queue;
-    sc_queue_init(&queue);
-
-    assert(sc_queue_is_empty(&queue));
-
-    struct foo v1 = { .value = 42 };
-    struct foo v2 = { .value = 27 };
-
-    sc_queue_push(&queue, next, &v1);
-    sc_queue_push(&queue, next, &v2);
-
-    struct foo *foo;
-
-    assert(!sc_queue_is_empty(&queue));
-    sc_queue_take(&queue, next, &foo);
-    assert(foo->value == 42);
-
-    assert(!sc_queue_is_empty(&queue));
-    sc_queue_take(&queue, next, &foo);
-    assert(foo->value == 27);
-
-    assert(sc_queue_is_empty(&queue));
-}
-
-int main(int argc, char *argv[]) {
-    (void) argc;
-    (void) argv;
-
-    test_queue();
-    return 0;
-}