Remove unused annotation

core/network/src/commonMain/kotlin/com/google/samples/apps/nowinandroid/core/network/fake/FakeNiaNetworkDataSource.kt

@@ -24,7 +24,6 @@ import com.google.samples.apps.nowinandroid.core.network.model.NetworkChangeList
 import com.google.samples.apps.nowinandroid.core.network.model.NetworkNewsResource
 import com.google.samples.apps.nowinandroid.core.network.model.NetworkTopic
 import kotlinx.coroutines.withContext
-import kotlinx.serialization.ExperimentalSerializationApi
 import kotlinx.serialization.json.Json
 import me.tatarka.inject.annotations.Inject
 
@@ -36,13 +35,11 @@ class FakeNiaNetworkDataSource @Inject constructor(
     private val networkJson: Json,
 ) : NiaNetworkDataSource {
 
-    @OptIn(ExperimentalSerializationApi::class)
     override suspend fun getTopics(ids: List<String>?): List<NetworkTopic> =
         withContext(ioDispatcher) {
             networkJson.decodeFromString(TOPICS_DATA)
         }
 
-    @OptIn(ExperimentalSerializationApi::class)
     override suspend fun getNewsResources(ids: List<String>?): List<NetworkNewsResource> =
         withContext(ioDispatcher) {
             networkJson.decodeFromString(NEWS_DATA)