Test Ruby 4.0 compatibility

[bastelfreak]

No description provided.

[ekohl]

  1) Puppet::Util::Execution#execpipe should set LANG to C avoid localized output
     Failure/Error:
       open("| #{command_str} 2>&1") do |pipe| # rubocop:disable Security/Open
         yield pipe
       end
     Errno::ENOENT:
       No such file or directory @ rb_sysopen - | echo $LANG 2>&1
     # ./lib/puppet/util/execution.rb:82:in 'File#initialize'
     # ./lib/puppet/util/execution.rb:82:in 'Kernel#open'
     # ./lib/puppet/util/execution.rb:82:in 'block in Puppet::Util::Execution.execpipe'
     # ./lib/puppet/util.rb:88:in 'Puppet::Util.withenv'
     # ./lib/puppet/util/execution.rb:80:in 'Puppet::Util::Execution.execpipe'
     # ./spec/integration/util/execution_spec.rb:9:in 'block (3 levels) in <top (required)>'
     # ./spec/spec_helper.rb:182:in 'block (2 levels) in <top (required)>'
     # ./vendor/bundle/ruby/4.0.0/gems/webmock-3.26.1/lib/webmock/rspec.rb:39:in 'block (2 levels) in <top (required)>'
     # util/rspec_runner:47:in 'Parallel::RSpec::Runner#run'
     # util/rspec_runner:61:in '<main>'

Completely untested, but #295 may solve this.