build kotlin version that works with current jdk in Debian/testing

After kotlin is bootstrapped with OpenJDK 8, then kotlin needs to be upgraded to build with a current Java version. By the time this is done it'll probably be targetting openjdk-17, but maybe still openjdk-11. Ultimately, we need the version of Kotlin used by the Android SDK version that we are building.

• find highest kotlin version that will build using kotlin-bootstrap
• update dependencies as required by that kotlin version
• get new kotlin version building with default-jdk instead of openjdk-8
• debian/copyright review for new things
• Uploaded
• Repeat until we get to the kotlin version needed by the Android SDK