Fix build on macOS (#63)

Pulling in the change from the following ATS PR (but putting the include
in alphabetical order):
apache/trafficserver#8669

Co-authored-by: bneradt <[email protected]>

Author: bneradt

code/include/swoc/swoc_ip.h

@@ -6,6 +6,7 @@
  */
 
 #pragma once
+#include <array>
 #include <climits>
 #include <netinet/in.h>
 #include <string_view>