[CI] Drop EOL jruby 9.3

[larouxn]

Proposing we drop EOL jruby 9.3 from and add jruby 10.1 to our CI matrix. https://endoflife.date/jruby

Inspired by #2992 (comment).

[larouxn]

Apparently some work needs to be done to add support for jruby 10.1. #3003

EDIT: it appears pry-nav does not work well with jruby 10.1. It also appears to be abandoned. Unfortunately it looks like pry-nav was specifically added for jruby debugging but it seems that may no longer work/be possible, we may need to remove it. Maybe replaceable with ruby-debug, not sure, haven't used it.

elasticsearch-ruby/elasticsearch-api/Gemfile

Lines 30 to 34 in 236f137

	if defined?(JRUBY_VERSION)
	gem 'pry-nav'
	else
	gem 'debug'
	end

elasticsearch-ruby/elasticsearch-api/spec/spec_helper.rb

Lines 24 to 28 in 236f137

	if defined?(JRUBY_VERSION)
	require 'pry-nav'
	else
	require 'debug'
	end

EDIT: Maybe we simply omit jruby 10.1 from this PR and open an issue for adding support for it.

[larouxn]

I dropped adding jruby 10.1 from this PR as it requires additional work and logged adding support for it in #3003.