build: do not include deleted directory

`deps/uv/src/ares` hasn't existed since
libuv/libuv@41b1265af8329131154539cb0d1eda57758b62be (mid 2012).

PR-URL: https://github.com/nodejs/node/pull/16384


Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>
Reviewed-By: Anatoli Papirovski <apapirovski@mac.com>
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Gibson Fahnestock <gibfahn@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>