Update dependency org.jetbrains.kotlin.multiplatform to v2.2.21

Author: renovate[bot]

gradle/libs.versions.toml

@@ -7,7 +7,7 @@ android-targetSdk = "36"
 coroutines = "1.10.2"
 detekt = "1.23.8"
 filekit = "0.12.0"
-kotlin = "2.2.20"
+kotlin = "2.2.21"
 
 [libraries]
 androidx-activity-compose = "androidx.activity:activity-compose:1.11.0"