replace TODO for pipelineStepsHolder with default realization

tgbotapi.core/src/commonMain/kotlin/dev/inmo/tgbotapi/bot/Ktor/KtorRequestsExecutor.kt

@@ -58,7 +58,7 @@ class KtorRequestsExecutor(
     excludeDefaultFactories: Boolean = false,
     private val requestsLimiter: RequestLimiter = ExceptionsOnlyLimiter(),
     private val jsonFormatter: Json = nonstrictJsonFormat,
-    private val pipelineStepsHolder: KtorPipelineStepsHolder = TODO()
+    private val pipelineStepsHolder: KtorPipelineStepsHolder = KtorPipelineStepsHolder
 ) : BaseRequestsExecutor(telegramAPIUrlsKeeper) {
     private val callsFactories: List<KtorCallFactory> = callsFactories.run {
         if (!excludeDefaultFactories) {

tgbotapi.core/src/commonMain/kotlin/dev/inmo/tgbotapi/bot/ktor/KtorPipelineStepsHolder.kt

@@ -70,4 +70,6 @@ interface KtorPipelineStepsHolder {
         request: Request<T>,
         callsFactories: List<KtorCallFactory>
     ): T = result.getOrThrow()
+
+    companion object : KtorPipelineStepsHolder
 }