unit: drop withRuby_3_2 flag

Ruby 3.2 will go EOL during the Nixpkgs 25.11 release cycle.

pkgs/by-name/un/unit/package.nix

@@ -12,8 +12,6 @@
   php82,
   withPerl ? true,
   perl,
-  withRuby_3_2 ? false,
-  ruby_3_2,
   withSSL ? true,
   openssl ? null,
   withIPv6 ? true,
@@ -56,7 +54,6 @@ stdenv.mkDerivation rec {
   ]
   ++ optional withPHP82 php82-unit
   ++ optional withPerl perl
-  ++ optional withRuby_3_2 ruby_3_2
   ++ optional withSSL openssl;
 
   configureFlags = [
@@ -76,7 +73,6 @@ stdenv.mkDerivation rec {
     ${optionalString withPython3 "./configure python --module=python3  --config=python3-config  --lib-path=${python3}/lib"}
     ${optionalString withPHP82 "./configure php    --module=php82    --config=${php82-unit.unwrapped.dev}/bin/php-config --lib-path=${php82-unit}/lib"}
     ${optionalString withPerl "./configure perl   --module=perl     --perl=${perl}/bin/perl"}
-    ${optionalString withRuby_3_2 "./configure ruby   --module=ruby32   --ruby=${ruby_3_2}/bin/ruby"}
   '';
 
   passthru.tests = {