[FLINK-36923] Bump flink version to 1.20.0, adapt CI workflow

[lvyanquan]

Bump flink version to 1.19.1 to support Flink 1.20

[boring-cyborg]

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[lvyanquan]

Hi @ferenc-csaky

Could you help to review this? and I would greatly appreciate it if you could share your thoughts on this bump plan and the next release.

[ferenc-csaky]

Hi, thanks for your contribution! I am planning to try to include at least JDK 17 (and possibly 21) support for the next release, which will require to bump HBase version and pretty much all Hadoop related dependencies. I spent some time on that before releasing 4.0, but it is not trivial and I ran into some runtime issues, that's where I decided to cut scope and release to only JDK8 and 11.

Including these version updates makes sense anyway, so I do not see a problem merging it on its own.

[ferenc-csaky]

We should remove 1.18 from the CI workflows.

[ferenc-csaky]

@lvyanquan Any specific reason to remove 1.19 as well? I am not necessarily against it, but since 1.19 is still supported I believe it would make sense to go with 1.19, 1.20 support as the default setup if there are no other things to consider. WDYT?

[lvyanquan]

Hi, @ferenc-csaky.

The reason of directly bumping to 1.20 is because I want to speed up the adaptation to 1.20 and try to start integrating with Flink 2.0, and we've released flink-connector-hbase 4.0.0 that supported Flink 1.18 & Flink 1.19, so we can release a 4.0.1 for bug fix in Flink 1.19.

However, this is not a mandatory requirement for me, so I also want to confirm with you whether this is feasible.
If this is too radical, I will revert back to bumping 1.19 and support both 1.19 and 1.20.

[boring-cyborg]

Awesome work, congrats on your first merged pull request!