upgrade gecko. gradle, deps

packages/flutter_singbox_proxy/android/build.gradle

@@ -2,15 +2,13 @@ group = "eu.weblibre.flutter_singbox_proxy"
 version = "1.0-SNAPSHOT"
 
 buildscript {
-    ext.kotlin_version = "2.3.21"
     repositories {
         google()
         mavenCentral()
     }
 
     dependencies {
-        classpath("com.android.tools.build:gradle:8.13.2")
-        classpath("org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version")
+        classpath("com.android.tools.build:gradle:9.2.1")
     }
 }
 
@@ -32,21 +30,16 @@ def requireWebLibreGoMobileAar = {
 }
 
 apply plugin: "com.android.library"
-apply plugin: "kotlin-android"
 
 android {
     namespace = "eu.weblibre.flutter_singbox_proxy"
-    compileSdk = 36
+    compileSdk = 37
 
     compileOptions {
         sourceCompatibility = JavaVersion.VERSION_17
         targetCompatibility = JavaVersion.VERSION_17
     }
 
-    kotlinOptions {
-        jvmTarget = JavaVersion.VERSION_17
-    }
-
     sourceSets {
         main.java.srcDirs += "src/main/kotlin"
         test.java.srcDirs += "src/test/kotlin"
@@ -69,13 +62,19 @@ android {
     }
 }
 
+kotlin {
+    compilerOptions {
+        jvmTarget = org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_17
+    }
+}
+
 dependencies {
     requireWebLibreGoMobileAar()
     compileOnly(files(weblibreGoMobileAar))
 
-    implementation("com.squareup.okhttp3:okhttp:4.12.0")
+    implementation("com.squareup.okhttp3:okhttp:5.4.0")
 
-    testImplementation("org.json:json:20250517")
+    testImplementation("org.json:json:20260522")
     testImplementation("org.jetbrains.kotlin:kotlin-test")
     testImplementation("org.mockito:mockito-core:5.23.0")
 }