remove ruby execution #11236
Description
With java execution we no longer need the ruby one. There are know issues blocking this removal:
The Java Execution Engine has been the default engine since Logstash 7.0, and is capable of using plugins written in either Ruby or Java; removing the Ruby Execution Engine will not affect our ability to run existing pipelines, but will greatly reduce the surface area of all features and fixes within the engine(s), since we will no longer need to target two engines simultaneously.