Update the minimum version for running Data Prepper to JDK 21 from JDK 11.
(The original proposal from Oct 2023 was to update to JDK 17. Releasing with JDK 21 as the minimum now that it is the latest LTS will give us more language features and fewer versions to support)
Update the minimum version for running Data Prepper to JDK 21 from JDK 11.
(The original proposal from Oct 2023 was to update to JDK 17. Releasing with JDK 21 as the minimum now that it is the latest LTS will give us more language features and fewer versions to support)