💚 Fix CI for truffleruby

Author: pboling

Gemfile.lock

@@ -173,6 +173,7 @@ GEM
 PLATFORMS
   arm64-darwin-22
   arm64-darwin-24
+  ruby
   x86_64-darwin-19
   x86_64-linux
 
@@ -198,4 +199,4 @@ DEPENDENCIES
   yard-junk (~> 0.0, >= 0.0.10)
 
 BUNDLED WITH
-   2.6.4
+   2.6.5

spec/version_gem/ruby_spec.rb

@@ -4,7 +4,7 @@
 require "version_gem/ruby"
 
 RSpec.describe(VersionGem::Ruby) do
-  let(:engine) { "ruby" }
+  let(:engine) { RUBY_ENGINE }
 
   it "is a module" do
     expect(described_class).is_a?(Module)