Replace setup-scala with setup-java

[mijicd]

Summary

• replaces setup-scala with setup-java
• sets Java 17 as default

[sideeffffect]

IMHO we should keep JVM version 8 as the base version and use it everywhere. Other JVM versions, like 11 or 17 should be then tested only in the testJvms.

The motivation is that this will make sure that all things work on the widest range of JVM versions -- this is one of Scala's biggest strengths, it is a powerful language that you can run even on an "old" JVM 8.

[sideeffffect]

The purpose of the task testJvms is to test on other JVM versions besides the base one, so it should stay ['11', '17'].

[mijicd]

It should not, as the base one is now 17.

[mijicd]

The motivation is that this will make sure that all things work on the widest range of JVM versions -- this is one of Scala's biggest strengths, it is a powerful language that you can run even on an "old" JVM 8.

If I'm not mistaken, that's the whole purpose behind the testJvms.

[mijicd]

@adamgfraser Could you please sync the series/2.x branch?

[adamgfraser]

@mijicd Will do!

[sideeffffect]

If I'm not mistaken, that's the whole purpose behind the testJvms.

But how about the other actions, like lint, compile, publishLocal or website? Shouldn't we primarily test them on 8 (instead of 17)? 🤔

[mijicd]

publishLocal and publish are still running on 8, due to the downward dependency. Regarding the other ones, I don't see that we're risking anything with migration to 17.

[sideeffffect]

fair enough 👍