[NOTICE][IMPORTANT] Must open a new PR when backporting patches to branch-2

[Duo Zhang]

HBASE-28676 and HBASE-28677 have been merged.

Now for master the pre commit will check java 17 build only.

So for all committers, please notice that, when you want to apply a
patch to branch-2, you MUST open a PR against branch-2 instead of just
cherry-picking the patch for master and then push, because we need to
make sure that the patch can also work with java8 and java 11.

Feel free to reply here if you have any questions.

Thanks.