Added derivation for the environment of ruboocop and solargraph (PAIN)

modules/languages/ruby/format_derivation.nix

@@ -0,0 +1,38 @@
+{
+  pkgs,
+  stdenv,
+}: let
+  formatter-env = with pkgs;
+    bundlerEnv {
+      name = "Gem dependencies";
+      inherit self;
+      ruby = ruby_3_2;
+      gemdir = ./.;
+
+      gemConfig =
+        pkgs.defaultGemConfig
+        // {
+          nokogiri = attrs: {
+            buildFlags = ["--use-system-libraries"]; # "--with-zlib-include=${pkgs.zlib}/include/libxml2"];
+          };
+        };
+    };
+in
+  stdenv.mkDerivation {
+    name = "Format environment";
+    nativeBuildInputs = [
+      pkgs.libxslt
+      pkgs.zlib
+      pkgs.libxml2
+      pkgs.pkg-config
+    ];
+
+    # Add the derivation to the PATH
+    buildInputs = [
+      pkgs.libxslt
+      pkgs.zlib
+      pkgs.libxml2
+      pkgs.pkg-config
+      formatter-env
+    ];
+  }