chore(deps): update kotlin to v2.3.21 (#5228)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

gradle/libs.versions.toml

@@ -18,7 +18,7 @@ koin = "4.2.1"
 koin-plugin = "1.0.0-RC2"
 
 # Kotlin
-kotlin = "2.3.21-RC2"
+kotlin = "2.3.21"
 kotlinx-coroutines-android = "1.10.2"
 kotlinx-datetime = "0.7.1"
 kotlinx-serialization = "1.11.0"