bind.dnsutils: remove reference to main output

The `delv` executable references `$out/etc/bind.keys` but a copy of that
file is included in binary anyway. DNSSEC validation still works when
the reference is removed.

pkgs/by-name/bi/bind/package.nix

@@ -2,6 +2,7 @@
   stdenv,
   lib,
   fetchurl,
+  removeReferencesTo,
   darwin,
   perl,
   pkg-config,
@@ -49,6 +50,7 @@ stdenv.mkDerivation (finalAttrs: {
   nativeBuildInputs = [
     perl
     pkg-config
+    removeReferencesTo
   ];
   buildInputs =
     [
@@ -128,6 +130,10 @@ stdenv.mkDerivation (finalAttrs: {
       sed -i '/^ISC_TEST_ENTRY(tcpdns_recv_one/d' tests/isc/netmgr_test.c
     '';
 
+  postFixup = ''
+    remove-references-to -t "$out" "$dnsutils/bin/delv"
+  '';
+
   passthru = {
     tests = {
       withCheck = finalAttrs.finalPackage.overrideAttrs { doCheck = true; };