[SUMMARY] Flink 2.0 Release Sync 08/28/2024

[Xintong Song <to...@gmail.com>]

Hi devs,

Here's a summary of today's release sync.

## About work items

   - Java supports
      - Java 21 will be supported in 2.0
      - Java 17 will be made default in 2.0
      - Supports for Java 8 will be dropped in 2.0
      - Martijn will start a FLIP discussion on deprecating support for
      Java 11. It will not be directly removed in 2.0
   - We will not continue with the REST API and Metrics work items in 2.0
   - We are still collecting new features for this release cycle. Please
   reachout to the release managers.

## About the Preview Release

   - *All breaking changes should be completed in the preview release
   (end-of-Sep.)*
      - There are a lot of internal usages of Source/SinkFunction and
      legacy TableSource/SinkFunction, which cannot be all migrated before the
      preview release. We will first move the public APIs to internal
interfaces,
      then migrate the internal usges gradually.
      - In future, we will update the depreciation process to require
      migrating of internal usages in advance.
   - *We have created a new version "2.0-preview" on Jira.*
      - FixVersion of tickets targeting the preview release, or with code
      changes merged into the master branch between the 1.20.0 and 2.0-preview,
      should be set to 2.0-preview.
      - We will soon move existing tickets from "2.0.0" to this version.
         - We'll check for all deprecated APIs before the preview release,
   making sure all deprecated APis are either removed or we know why they are
   not removed.

Best,

Xintong