[rubygems/rubygems] Test with Ruby 3.4

https://github.com/rubygems/rubygems/commit/23d06195fa

lib/bundler/process_lock.rb

@@ -6,7 +6,7 @@ module Bundler
       lock_file_path = File.join(bundle_path, "bundler.lock")
       base_lock_file_path = lock_file_path.delete_suffix(".lock")
 
-      require "fileutils" if Bundler.rubygems.provides?("< 3.5.23")
+      require "fileutils" if Bundler.rubygems.provides?("< 3.6.0")
 
       begin
         SharedHelpers.filesystem_access(lock_file_path, :write) do

lib/bundler/rubygems_ext.rb

@@ -442,7 +442,7 @@ module Gem
     end
   end
 
-  unless Gem.rubygems_version >= Gem::Version.new("3.5.23")
+  if Gem.rubygems_version < Gem::Version.new("3.6.0")
     class Package; end
     require "rubygems/package/tar_reader"
     require "rubygems/package/tar_reader/entry"

spec/bundler/runtime/setup_spec.rb

@@ -1554,7 +1554,7 @@ end
       RUBY
 
       expect(last_command.stdboth).not_to include "FAIL"
-      expect(err).to include "private method `gem'"
+      expect(err).to match(/private method [`']gem'/)
     end
 
     it "keeps Kernel#require private" do