refactor: emit jsonobject-based models without any

Regen types in https://github.com/hyodotdev/openiap-gql/releases/tag/1.0.8

Author: hyochan

openiap/build.gradle.kts

@@ -53,6 +53,7 @@ dependencies {
 
     // Google Play Billing Library (align with app/lib v8)
     api("com.android.billingclient:billing-ktx:8.0.0")
+    api("org.jetbrains.kotlinx:kotlinx-serialization-json:1.7.3")
 
     // Kotlin Coroutines
     implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.9.0")