Support Kotlin 2.1.20

[neckbosov]

Kotlin 2.1.20 has just been released, please add support for it, looks like it's necessary to merge #1268, maybe something else.

I use rules_kotlin and kapt and would like to try the new k2 mode for kapt. It seems like there is no way to enable it in the current rules version, in kotlin 2.1.20 it's enabled by default.

[tempacc21]

Any updates here?

[Bencodes]

This is now supported in the main branch.