Swap archived JakeWharton serialization converter for Retrofit's upstream (#1910) (#1925)

The `com.jakewharton.retrofit:retrofit2-kotlinx-serialization-converter`
artifact was archived when the converter was upstreamed into Retrofit as
`com.squareup.retrofit2:converter-kotlinx-serialization`. The JW artifact
is frozen at 1.0.0 (built against Retrofit 2.x/OkHttp 4.x) and Dependabot
will never update it — after the retrofit 2→3 (#1855) and okhttp 4→5
(#1854) major bumps it was the one leg of the network stack still pinned
to the old majors.

Swap the coordinate to the upstream converter (versioned with retrofit,
so it tracks the same version.ref and dependabot bumps) and update the
`asConverterFactory` import at both call sites. The API is identical.

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

Author: bmander

gradle/libs.versions.toml

@@ -69,7 +69,6 @@ composeBom = "2026.06.01"
 materialIcons = "1.7.8"
 retrofit = "3.0.0"
 okhttp = "5.4.0"
-retrofitKotlinxConverter = "1.0.0"
 kotlinxSerializationJson = "1.11.0"
 coroutines = "1.11.0"
 material = "1.14.0"
@@ -151,7 +150,7 @@ hilt-android-compiler = { module = "com.google.dagger:hilt-android-compiler", ve
 retrofit = { module = "com.squareup.retrofit2:retrofit", version.ref = "retrofit" }
 okhttp = { module = "com.squareup.okhttp3:okhttp", version.ref = "okhttp" }
 okhttp-logging-interceptor = { module = "com.squareup.okhttp3:logging-interceptor", version.ref = "okhttp" }
-retrofit-kotlinx-serialization-converter = { module = "com.jakewharton.retrofit:retrofit2-kotlinx-serialization-converter", version.ref = "retrofitKotlinxConverter" }
+retrofit-kotlinx-serialization-converter = { module = "com.squareup.retrofit2:converter-kotlinx-serialization", version.ref = "retrofit" }
 kotlinx-serialization-json = { module = "org.jetbrains.kotlinx:kotlinx-serialization-json", version.ref = "kotlinxSerializationJson" }
 apollo-runtime = { module = "com.apollographql.apollo:apollo-runtime", version.ref = "apollo" }
 kotlinx-coroutines-android = { module = "org.jetbrains.kotlinx:kotlinx-coroutines-android", version.ref = "coroutines" }

onebusaway-android/src/main/java/org/onebusaway/android/api/net/ObaApiProvider.kt

@@ -16,14 +16,14 @@
 package org.onebusaway.android.api.net
 
 import android.net.Uri
-import com.jakewharton.retrofit2.converter.kotlinx.serialization.asConverterFactory
 import java.io.IOException
 import javax.inject.Inject
 import javax.inject.Singleton
 import kotlinx.serialization.json.Json
 import okhttp3.MediaType.Companion.toMediaType
 import okhttp3.OkHttpClient
 import org.onebusaway.android.api.contract.ObaWebService
+import retrofit2.converter.kotlinx.serialization.asConverterFactory
 import retrofit2.Retrofit
 
 /**

onebusaway-android/src/main/java/org/onebusaway/android/app/di/NetworkModule.kt

@@ -35,7 +35,7 @@ import org.onebusaway.android.api.contract.RegionsWebService
 import org.onebusaway.android.api.contract.ReminderWebService
 import org.onebusaway.android.api.contract.SurveyWebService
 import org.onebusaway.android.api.contract.WeatherWebService
-import com.jakewharton.retrofit2.converter.kotlinx.serialization.asConverterFactory
+import retrofit2.converter.kotlinx.serialization.asConverterFactory
 import retrofit2.Retrofit
 
 /**