Fix Dataloader#with for JRuby

[rmosolgo]

Fixes #5541

Apparently JRuby 10+ handles this fine, so I reworked these conditionals to allow it to use the else branch instead. I ran the script from #5541 and it passed with this change:

RUBY_ENGINE: jruby
RUBY_VERSION: 3.4.5
graphql gem version: 2.6.1

Attempting: dataloader.with(KeywordSource, name: 'test', value: 42).load('key1')
SUCCESS: "test:42:key1"

I don't have any JRuby or TruffleRuby CI set up, though 🙈

I got the RUBY_ENGINE value for TruffleRuby ("truffleruby") here: https://www.graalvm.org/22.0/reference-manual/ruby/Compatibility/