Bump kotlin 2.1.0, binary-compatibility-validator 0.16.3

[egorikftp]

• closes Kotlin 2.1.0 runtime crash #566

tests passed

added test.api file due to

[egorikftp]

@ajalt could you please take a look? 🙂

[VladRassokhin]

Well, that breaks backward compatibility with Kotlin 1.9, so it's impossible to use clikt 5.0.2 if your project uses kotlin 1.9.
Yet it was possible with clikt 5.0.1. Quite a major change for only a 'patch' version update.

Class 'com.github.ajalt.clikt.core.CliktCommand' was compiled with an incompatible version of Kotlin. The actual metadata version is 2.1.0, but the compiler version 1.9.0 can read versions up to 2.0.0.