Fix test falling due to unexpected mockk behaviour (looks like a bug)

Author: nsk90

tests/src/commonTest/kotlin/ru/nsk/kstatemachine/state/StateCleanupTest.kt

@@ -10,37 +10,45 @@ package ru.nsk.kstatemachine.state
 import io.kotest.core.spec.style.FreeSpec
 import io.kotest.matchers.shouldBe
 import io.mockk.coVerify
-import io.mockk.spyk
+import io.mockk.mockk
 import ru.nsk.kstatemachine.CoroutineStarterType
 import ru.nsk.kstatemachine.createTestStateMachine
 import ru.nsk.kstatemachine.state.StateCleanupTestData.State1
 import ru.nsk.kstatemachine.statemachine.destroyBlocking
 
 private object StateCleanupTestData {
-    class State1 : DefaultState("state1")
+    class State1(private val onCleanupListener: () -> Unit) : DefaultState("state1") {
+        override suspend fun onCleanup() {
+            super.onCleanup()
+            onCleanupListener()
+        }
+    }
 }
 
 class StateCleanupTest : FreeSpec({
     CoroutineStarterType.entries.forEach { coroutineStarterType ->
         "$coroutineStarterType" - {
             "cleanup is not called" {
-                val state = spyk<State1>()
+                val listener = mockk<() -> Unit>(relaxed = true)
+                val state = State1(listener)
                 useInMachine(coroutineStarterType, state)
-                coVerify(inverse = true) { state.onCleanup() }
+                coVerify(inverse = true) { listener() }
             }
 
             "cleanup is called on machine manual destruction" {
-                val state = spyk<State1>()
+                val listener = mockk<() -> Unit>(relaxed = true)
+                val state = State1(listener)
                 useInMachine(coroutineStarterType, state).destroyBlocking()
-                coVerify(exactly = 1) { state.onCleanup() }
+                coVerify(exactly = 1) { listener() }
             }
 
             "cleanup is called on machine auto destruction" {
-                val state = spyk<State1>()
+                val listener = mockk<() -> Unit>(relaxed = true)
+                val state = State1(listener)
                 val machine1 = useInMachine(coroutineStarterType, state)
                 val machine2 = useInMachine(coroutineStarterType, state)
 
-                coVerify(exactly = 1) { state.onCleanup() }
+                coVerify(exactly = 1) { listener() }
                 machine1.isDestroyed shouldBe true
                 machine2.isDestroyed shouldBe false
             }