android: Update to Kotlin 1.8.21

src/android/build.gradle.kts

@@ -2,7 +2,7 @@
 plugins {
     id("com.android.application") version "8.0.1" apply false
     id("com.android.library") version "8.0.1" apply false
-    id("org.jetbrains.kotlin.android") version "1.8.10" apply false
+    id("org.jetbrains.kotlin.android") version "1.8.21" apply false
 }
 
 tasks.register("clean").configure {