Revert "Temporary revert to Kotlin 1.5.31."

This reverts commit 21ae5386.

skiko/build.gradle.kts

@@ -9,7 +9,7 @@ import org.jetbrains.kotlin.gradle.tasks.KotlinNativeCompile
 import org.gradle.api.tasks.testing.logging.TestExceptionFormat
 
 plugins {
-    kotlin("multiplatform") version "1.5.31"
+    kotlin("multiplatform") version "1.6.10"
     `maven-publish`
     signing
     id("org.gradle.crypto.checksum") version "1.1.0"
@@ -1216,5 +1216,5 @@ tasks.withType<AbstractTestTask> {
 }
 
 rootProject.plugins.withType<org.jetbrains.kotlin.gradle.targets.js.nodejs.NodeJsRootPlugin> {
-    rootProject.the<org.jetbrains.kotlin.gradle.targets.js.nodejs.NodeJsRootExtension>().nodeVersion = "17.0.0"
+    rootProject.the<org.jetbrains.kotlin.gradle.targets.js.nodejs.NodeJsRootExtension>().nodeVersion = "16.0.0"
 }