[K2] Too verbose messaging about Dokka K2 in preview

[atyrin]

> Configure project :
Dokka's K2 Analysis is being used. It is still under active development and is thus experimental. It can be the cause of failed builds or incorrectly generated documentation. If you encounter an issue, please consider reporting it: https://github.com/Kotlin/dokka/issues
Dokka's K2 Analysis is being used. It is still under active development and is thus experimental. It can be the cause of failed builds or incorrectly generated documentation. If you encounter an issue, please consider reporting it: https://github.com/Kotlin/dokka/issues
Dokka's K2 Analysis is being used. It is still under active development and is thus experimental. It can be the cause of failed builds or incorrectly generated documentation. If you encounter an issue, please consider reporting it: https://github.com/Kotlin/dokka/issues
Dokka's K2 Analysis is being used. It is still under active development and is thus experimental. It can be the cause of failed builds or incorrectly generated documentation. If you encounter an issue, please consider reporting it: https://github.com/Kotlin/dokka/issues
Dokka's K2 Analysis is being used. It is still under active development and is thus experimental. It can be the cause of failed builds or incorrectly generated documentation. If you encounter an issue, please consider reporting it: https://github.com/Kotlin/dokka/issues
Dokka's K2 Analysis is being used. It is still under active development and is thus experimental. It can be the cause of failed builds or incorrectly generated documentation. If you encounter an issue, please consider reporting it: https://github.com/Kotlin/dokka/issues
Dokka's K2 Analysis is being used. It is still under active development and is thus experimental. It can be the cause of failed builds or incorrectly generated documentation. If you encounter an issue, please consider reporting it: https://github.com/Kotlin/dokka/issues
Dokka's K2 Analysis is being used. It is still under active development and is thus experimental. It can be the cause of failed builds or incorrectly generated documentation. If you encounter an issue, please consider reporting it: https://github.com/Kotlin/dokka/issues
Dokka's K2 Analysis is being used. It is still under active development and is thus experimental. It can be the cause of failed builds or incorrectly generated documentation. If you encounter an issue, please consider reporting it: https://github.com/Kotlin/dokka/issues
Dokka's K2 Analysis is being used. It is still under active development and is thus experimental. It can be the cause of failed builds or incorrectly generated documentation. If you encounter an issue, please consider reporting it: https://github.com/Kotlin/dokka/issues
Dokka's K2 Analysis is being used. It is still under active development and is thus experimental. It can be the cause of failed builds or incorrectly generated documentation. If you encounter an issue, please consider reporting it: https://github.com/Kotlin/dokka/issues
Dokka's K2 Analysis is being used. It is still under active development and is thus experimental. It can be the cause of failed builds or incorrectly generated documentation. If you encounter an issue, please consider reporting it: https://github.com/Kotlin/dokka/issues
Dokka's K2 Analysis is being used. It is still under active development and is thus experimental. It can be the cause of failed builds or incorrectly generated documentation. If you encounter an issue, please consider reporting it: https://github.com/Kotlin/dokka/issues

May be we can reduce it to one message? Or at least move from the Gradle configuration phase to the dokka task execution?

[whyoleg]

should be fixed in scope of #3743