Bump Kotlin compiler to 2.3.21

Summary:
Upgrade the Kotlin compiler version in the project to the latest public stable release (2.3.21). Also bump the apiVersion to KOTLIN_2_1 in all four gradle-plugin build files to resolve deprecation warnings for 2.0, and replace the deprecated -Xjvm-default compiler option in ReactAndroid with -jvm-default=no-compatibility.

## Changelog:
[ANDROID] [CHANGED] - Bumped Kotlin version to 2.3.21 and Kotlin API version to 2.1

TAG=agy
CONV=2fc9825d-a86b-4fbb-ab9a-e7d467b57dd3

Author: mcorner

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 = "2.2.0"
+kotlin = "2.3.21"
 assertj = "3.25.1"
 ktfmt = "0.22.0"
 

packages/gradle-plugin/react-native-gradle-plugin/build.gradle.kts

@@ -64,7 +64,7 @@ kotlin { jvmToolchain(17) }
 
 tasks.withType<KotlinCompile>().configureEach {
   compilerOptions {
-    apiVersion.set(KotlinVersion.KOTLIN_2_0)
+    apiVersion.set(KotlinVersion.KOTLIN_2_1)
     // See comment above on JDK 11 support
     jvmTarget.set(JvmTarget.JVM_11)
     allWarningsAsErrors.set(

packages/gradle-plugin/settings-plugin/build.gradle.kts

@@ -54,7 +54,7 @@ kotlin { jvmToolchain(17) }
 
 tasks.withType<KotlinCompile>().configureEach {
   compilerOptions {
-    apiVersion.set(KotlinVersion.KOTLIN_2_0)
+    apiVersion.set(KotlinVersion.KOTLIN_2_1)
     // See comment above on JDK 11 support
     jvmTarget.set(JvmTarget.JVM_11)
     allWarningsAsErrors.set(

packages/gradle-plugin/shared-testutil/build.gradle.kts

@@ -27,7 +27,7 @@ kotlin { jvmToolchain(17) }
 
 tasks.withType<KotlinCompile>().configureEach {
   compilerOptions {
-    apiVersion.set(KotlinVersion.KOTLIN_2_0)
+    apiVersion.set(KotlinVersion.KOTLIN_2_1)
     // See comment above on JDK 11 support
     jvmTarget.set(JvmTarget.JVM_11)
     allWarningsAsErrors.set(

packages/gradle-plugin/shared/build.gradle.kts

@@ -33,7 +33,7 @@ kotlin { jvmToolchain(17) }
 
 tasks.withType<KotlinCompile>().configureEach {
   compilerOptions {
-    apiVersion.set(KotlinVersion.KOTLIN_2_0)
+    apiVersion.set(KotlinVersion.KOTLIN_2_1)
     // See comment above on JDK 11 support
     jvmTarget.set(JvmTarget.JVM_11)
     allWarningsAsErrors.set(

packages/react-native/ReactAndroid/build.gradle.kts

@@ -545,7 +545,7 @@ android {
   kotlin {
     compilerOptions {
       // Using '-Xjvm-default=all' to generate default java methods for interfaces
-      freeCompilerArgs = listOf("-Xjvm-default=all")
+      freeCompilerArgs = listOf("-jvm-default=no-compatibility")
       // Using -PenableWarningsAsErrors=true prop to enable allWarningsAsErrors
       allWarningsAsErrors = enableWarningsAsErrors()
     }

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

@@ -29,7 +29,7 @@ javax-inject = "1"
 jsc-android = "2026004.0.1"
 jsr305 = "3.0.2"
 junit = "4.13.2"
-kotlin = "2.2.0"
+kotlin = "2.3.21"
 ktfmt = "0.22.0"
 mockito = "3.12.4"
 mockito-kotlin = "3.2.0"