gnu: Remove c-ares-for-node.

The node-lts package can now be built using the standard c-ares package.

* gnu/packages/adns.scm (c-ares-for-node): Delete variable.

Change-Id: I9e613f2d4aeacb6079d69f5bef22d11eb8dc6b18

gnu/packages/adns.scm

@@ -161,25 +161,3 @@ multiple clients and programs with graphical user interfaces.")
      (arguments
       `(;; XXX: Tests require name resolution (the normal variant runs no tests).
         #:tests? #f)))))
-
-(define-public c-ares-for-node
-  (hidden-package
-   (package
-     (inherit c-ares)
-     (name "c-ares")
-     (version "1.18.1")
-     (source (origin
-               (method url-fetch)
-               (uri (string-append
-                     "https://c-ares.haxx.se/download/" name "-" version
-                     ".tar.gz"))
-               (sha256
-                (base32
-                 "1kxviskwsaa7dcgscvssxa8ps88pdq7kq4z93gxvz7sam2l54z8s"))))
-     (arguments
-      '(#:phases
-        (modify-phases %standard-phases
-          (add-before 'check 'filter-live-tests
-            (lambda _
-              ;; Filter tests that require internet access.
-              (setenv "GTEST_FILTER" "-*.Live*:*.FamilyV4*")))))))))