Add rake to the LOAD_PATH:

- There is a change in Rubygem 3.4.0 that I couldn't identify
  which makes `bundle exec ruby -r'rake'` to fail if rake is
  not in the Gemfile.
  This used to work with Rubygem 3.3.26 (last version in the 3.3 serie).

  Adding rake to the LOAD_PATH manually fixes it.

lib/ci_runner/runners/minitest_runner.rb

@@ -89,7 +89,7 @@ def start!
         env["RUBY"] = ruby_path.to_s if ruby_path&.exist?
         env["BUNDLE_GEMFILE"] = gemfile_path.to_s if gemfile_path&.exist?
 
-        execute_within_frame(env, "bundle exec ruby -r'rake/testtask' #{rakefile_path}")
+        execute_within_frame(env, "bundle exec ruby -I'#{rake_load_path}' -r'rake/testtask' #{rakefile_path}")
 
         DRb.stop_service
       end