Post Java 11 version bumps

[Jolanrensen]

Follow up for: #700

Fixes #696
Closes #699
Fixes #595
Unblocks #771

Bumps various versions that were previously blocked, like Jupyter, Kotest, etc.

Bumps java toolchain version to 21 to be able to update simple-git. I also bumped TC to 21

[zaleslaw]

Interesting, why it was added

[Jolanrensen]

I'm not sure either, probably because it extends List

[koperagen]

Hmm.. It seems that target jdk is now Java 21 too: https://openjdk.org/jeps/431 and not 11 as we intend. Try Xjdk-release=11 in compileKotlin freeCompilerArgs

[Jolanrensen]

I'm not sure actually, do you think jvmToolChain overrides

tasks.withType<KotlinCompile> {
    compilerOptions {
        jvmTarget = JvmTarget.JVM_11
    }
}

tasks.withType<JavaCompile> {
    sourceCompatibility = JavaVersion.VERSION_11.toString()
    targetCompatibility = JavaVersion.VERSION_11.toString()
}

?

It could also be that apiDump simply runs with jvm 21 because it's a gradle plugin. I'll test this

[Jolanrensen]

made an issue for it Kotlin/binary-compatibility-validator#290

[koperagen]

https://kotlinlang.org/docs/compiler-reference.html#jvm-target-version
JVM target only seems to affect bytecode. jdk release limits API too. I think binary validator is correct here and our library compiled against newer JDK API, while targeting JVM 11 bytecode

[Jolanrensen]

Ah I see, but if the target jvm is 11, then it's okay to compile it against a newer version, right? Having the target at 11 allows our users to set their projects to 11 and DF still works

[koperagen]

I believe we need to set jdk release to 11 and toolchain to 21

[Jolanrensen]

I think release and target overlap. I'll set it, but I think setting the target and sourceCompatibility does the same.
Edit: actually, I think the apiDump now works correctly :)

[Jolanrensen]

okay seems Kotlin 2.1 is sneaking in from some dependency, need to figure out which, because it makes our jupyter tests fail