[Task]: Single dockerhub repository for Flink job server container

[Abacn]

What needs to happen?

Each time a new Flink version is supported, we need to create a new dockerhub repo prior to the release process, which involves Apache Infra approval.

Conventionally, a Dockerhub repository contains versioned image of different base platforms, for example, official python image https://hub.docker.com/_/python/tags has tags like "3.9.19-slim-bullseye", "3-alpine3.19"

We should be able to publish Flink job servers into single repository, saying, apache/beam_flink_job_server, and use tag like 2.99.0-flink1.99

This involves refactoring and it is good to start when adding support of the next flink version

Issue Priority

Priority: 3 (nice-to-have improvement)

Issue Components

• [ ] Component: Python SDK
• [X] Component: Java SDK
• [ ] Component: Go SDK
• [ ] Component: Typescript SDK
• [ ] Component: IO connector
• [ ] Component: Beam YAML
• [ ] Component: Beam examples
• [ ] Component: Beam playground
• [ ] Component: Beam katas
• [ ] Component: Website
• [ ] Component: Spark Runner
• [ ] Component: Flink Runner
• [ ] Component: Samza Runner
• [ ] Component: Twister2 Runner
• [ ] Component: Hazelcast Jet Runner
• [ ] Component: Google Cloud Dataflow Runner

[kennknowles]

Pinging @je-ik and @thebozzcl explicitly here