Update dependency com.android.billingclient:billing-ktx to v6 (#2003)

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

Author: renovate[bot]

app/build.gradle.kts

@@ -118,7 +118,7 @@ dependencies {
     implementation(group = "com.google.j2objc", name = "j2objc-annotations", version = "2.8")
 
     implementation(group = "com.android.billingclient", name = "billing", version = "6.0.0")
-    implementation(group = "com.android.billingclient", name = "billing-ktx", version = "5.2.0")
+    implementation(group = "com.android.billingclient", name = "billing-ktx", version = "6.0.0")
     implementation(group = "androidx.multidex", name = "multidex", version = "2.0.1")
     implementation(group = "androidx.cardview", name = "cardview", version = "1.0.0")
     implementation(group = "androidx.recyclerview", name = "recyclerview", version = "1.3.0")