1.6.4

• Added TestScope.backgroundScope for launching coroutines that perform work in the background and need to be cancelled at the end of the test (#3287).
• Fixed the POM of kotlinx-coroutines-debug having an incorrect reference to kotlinx-coroutines-bom, which cause the builds of Maven projects using the debug module to break (#3334).
• Fixed the Publisher.await functions in kotlinx-coroutines-reactive not ensuring that the Subscriber methods are invoked serially (#3360). Thank you, @EgorKulbachka!
• Fixed a memory leak in withTimeout on K/N with the new memory model (#3351).
• Added the guarantee that all Throwable implementations in the core library are serializable (#3328).
• Moved the documentation to https://kotlinlang.org/api/kotlinx.coroutines/ (#3342).
• Various documentation improvements.