build+ci: support macOS on arm64

Refs: #5135
Change-Id: I86f1955366df12cfb8b3e6f9d5e9f202778cc211
diff --git a/COPYING.md b/COPYING.md
index 23f7b5d..2d8dce9 100644
--- a/COPYING.md
+++ b/COPYING.md
@@ -9,10 +9,10 @@
 - The Boost libraries are licensed under the
   [Boost Software License 1.0](https://www.boost.org/users/license.html)
 
-- CityHash is licensed under a
+- CityHash is licensed under the
   [MIT license](https://github.com/google/cityhash/blob/master/COPYING)
 
-- Libpcap is licensed under a
+- Libpcap is licensed under the
   [3-clause BSD license](https://github.com/the-tcpdump-group/libpcap/blob/master/LICENSE)
 
 - The WebSocket++ library is licensed under the terms of the