Move gnunet to the boneyard

Closes Homebrew/homebrew#30418.

Formula/gnunet.rb

@@ -1,26 +0,0 @@
-require 'formula'
-
-class Gnunet < Formula
-  homepage 'https://gnunet.org/'
-  url 'http://ftpmirror.gnu.org/gnunet/gnunet-0.9.5a.tar.gz'
-  mirror 'http://ftp.gnu.org/gnu/gnunet/gnunet-0.9.5a.tar.gz'
-  sha256 '1d600717eee1f952e23d192288850a67948e92e0b1dee5d950d111b2670cbed7'
-  revision 3
-
-  depends_on 'libidn'
-  depends_on 'libgcrypt'
-  depends_on 'libextractor'
-  depends_on 'libunistring'
-  depends_on 'curl' if MacOS.version < :lion # needs >= v7.20.1
-
-  def install
-    system "./configure", "--disable-debug",
-                          "--disable-dependency-tracking",
-                          "--prefix=#{prefix}"
-    system "make install"
-  end
-
-  test do
-    system "#{bin}/gnunet-search", "--version"
-  end
-end