Cache is deprecated

I am attempting to upgrade LogStash OSS (OpenSearch Image opensearchproject/logstash-oss-with-opensearch-output-plugin) from version 8.6.1 to 8.9.0

Everything looks good, upon LogStash start, it generates strange warning:
Sending Logstash logs to /usr/share/logstash/logs which is now configured via
/usr/share/logstash/vendor/bundle/jruby/2.6.0/gems/sinatra-2.2.4/lib/sinatra/base.rb:938: warning: constant Tilt::Cache is deprecated

From what i understood, logstash is using an old version of sinatra (2.2.4) . The sinatra is using a Ruby feature that is now deprecated per

Is it something we can ignore? Or It is a bug in LogStash itself and need to report it? (previous version did not not generate this warning)

Thank you !

Hi All,

Would you please advise me regarding above question?