Update Kotlin to 2.3.21 (#59535)

Summary:
Pull Request resolved: #59535

Update the Kotlin version in the React Native and Gradle plugin version catalogs from 2.2.10 to 2.3.21. Align the HelloWorld Android application's Kotlin declaration, previously 2.1.20, with the same version.

Keep the Gradle plugin's Kotlin 2.0 API compatibility setting and JVM targets unchanged; those settings are separate from the compiler and plugin version.

Changelog:
[Android][Changed] - Update Kotlin to 2.3.21

Differential Revision: D127799945

fbshipit-source-id: 8bf261a12c09d325d1688d1e8f0828ed559c6c4d

Author: cortinico

packages/gradle-plugin/gradle/libs.versions.toml

@@ -4,7 +4,7 @@ gson = "2.8.9"
 guava = "31.0.1-jre"
 javapoet = "1.13.0"
 junit = "4.13.2"
-kotlin = "2.2.10"
+kotlin = "2.3.21"
 assertj = "3.25.1"
 
 [libraries]

packages/react-native/gradle/libs.versions.toml

@@ -31,7 +31,7 @@ javax-inject = "1"
 jsc-android = "2026004.0.1"
 jsr305 = "3.0.2"
 junit = "4.13.2"
-kotlin = "2.2.10"
+kotlin = "2.3.21"
 mockito = "3.12.4"
 mockito-kotlin = "3.2.0"
 nexus-publish = "2.0.0"

private/helloworld/android/build.gradle

@@ -12,7 +12,7 @@ buildscript {
         compileSdkVersion = 37
         targetSdkVersion = 35
         ndkVersion = "28.2.13676358"
-        kotlinVersion = "2.1.20"
+        kotlinVersion = "2.3.21"
     }
     repositories {
         google()