downgrade kotlin and fix build

startup/plugin/src/nativeMain/kotlin/StartPluginSerializer.native.kt

@@ -0,0 +1,13 @@
+package dev.inmo.micro_utils.startup.plugin
+
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
+
+internal actual fun alternativeDeserialize(decoder: Decoder): StartPlugin? {
+    return null
+}
+
+internal actual fun alternativeSerialize(
+    encoder: Encoder,
+    value: StartPlugin
+): Boolean = false