Add support for jruby 10.1

**Is your feature request related to a problem? Please describe.**

It would be nice to see latest jruby 10.1 supported.

Inspired by https://github.com/elastic/elasticsearch-ruby/pull/3000

**Describe the solution you'd like**

jruby 10.1 should be added to the CI config and the codebase updated to support it. That said it may already work just fine without any runtime code changes.

**Describe alternatives you've considered**

Not an alternative but I already tried adding it and it failed CI due to `pry-nav`, see: https://github.com/elastic/elasticsearch-ruby/pull/3000#issuecomment-4902685975.

**Additional context**

See the PR and comment linked above.

Start with the CI configuration and the failure discussed in the linked pull request, especially the pry-nav dependency. Check whether the codebase already runs on JRuby 10.1, then update the CI coverage and resolve any compatibility failure. Done means the JRuby 10.1 CI job passes without breaking existing jobs.

Written by the indexing model from the issue text.