build: do not include deleted directory

`deps/uv/src/ares` hasn't existed since
libuv/libuv@41b1265 (mid 2012).

PR-URL: nodejs/node#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>

node.gyp

@@ -183,7 +183,6 @@
       'include_dirs': [
         'src',
         'tools/msvs/genfiles',
-        'deps/uv/src/ares',
         '<(SHARED_INTERMEDIATE_DIR)', # for node_natives.h
         'deps/nghttp2/lib/includes'
       ],