Core: Drop support for Java 8

[findepi]

Relates to: #10474

[findepi]

This PR can also help in unblocking parquet version bump: #10209 (comment)

Thanks @ajantha-bhat for linking the two!

@findepi: Are you still working on this? I think this one is more important than JDK 21 support.

Technically this PR is ready to go (i.e. please review!).
However, there is no agreement yet as to when this should be merged, see the thread on the mailing list.

[ajantha-bhat]

However, there is no agreement yet as to when this should be merged, see the thread on the mailing list.

Please have a separate discussion for dropping JDK 8 support. Mixing things can slowdown the decision making usually.
Also mention that it is needed to unblock the parquet bump.

[findepi]

@ajantha-bhat it's not really mixed. I intended the thread to focus on adding 21, but folks decided to focus on dropping 8, as this clearly is more important, so this is all the thread is about. I wish we could just change it's title...

[steveloughran]

• making java11 your base version is great -but you'll need a followup of 'cut hadoop-2' profile. this is a good thing
• java 22 is going to break a lost as they will cut Subject.doAs(), which used throughout multi-user services. just be aware that it'll be traumatic.

[findepi]

( rebased to resolve conflicts with now-merged #10474, no other changes )

[findepi]

Rebased to update formatting in flink/v1.19 classes.
I will move the baseline update commit to separate PR though.

[jbonofre]

LGTM, thanks. I will start the following PRs thanks to that !

[findepi]

Moved to 1.7.0 milestone per [VOTE] Drop Java 8 support in Iceberg 1.7.0 mail list thread. Will merge tomorrow.

[rdblue]

Thanks for getting this through, @findepi!

[steveloughran]

nice. now, who is going to do the "drop hadoop2 profile", so letting iceberg move to filesystem APIs written since 2016?

[Fokko]

@steveloughran do you want to do the honors @steveloughran?

[steveloughran]

can give it a go, its time I learned gradle properly. but busy with helping getting 3.4.1 out the door, including those final changes

[steveloughran]

@Fokko started that PR. #10932 ...looks like hive2 is dead too. This good in that it will significantly reduce test profiles -but it is going to make the PR at lot more complex. I think I may be getting out of my depth build-wise before very long