ruby: remove unsupported versions (#34927)

* remove EOL ruby versions for security and maintenance reasons.
* only expose ruby_MAJOR_MINOR to the top-level. we don't provide
guarantees for the TINY version.
* mark all related packages as broken
* switch the default ruby version from 2.3.x to 2.4.x

pkgs/development/tools/redis-dump/default.nix

@@ -9,6 +9,7 @@ bundlerEnv {
   buildInputs = [ perl autoconf ];
 
   meta = with lib; {
+    broken = true; # needs ruby 2.0
     description = "Backup and restore your Redis data to and from JSON";
     homepage    = http://delanotes.com/redis-dump/;
     license     = licenses.mit;

pkgs/development/tools/rhc/default.nix

@@ -1,4 +1,4 @@
-{ lib, bundlerEnv, ruby_2_2, stdenv, makeWrapper }:
+{ lib, bundlerEnv, ruby, stdenv, makeWrapper }:
 
 stdenv.mkDerivation rec {
   name = "rhc-1.38.7";
@@ -6,7 +6,7 @@ stdenv.mkDerivation rec {
   env = bundlerEnv {
     name = "rhc-1.38.7-gems";
 
-    ruby = ruby_2_2;
+    inherit ruby;
 
     gemdir = ./.;
   };
@@ -21,6 +21,7 @@ stdenv.mkDerivation rec {
   '';
 
   meta = with lib; {
+    broken = true; # requires ruby 2.2
     homepage = https://github.com/openshift/rhc;
     description = "OpenShift client tools";
     license = licenses.asl20;