[Gradle, MPP] Mark KotlinTest.ignoreRunFailures as @Internal

This change is also done in order to preserve up-to-date state of successfully executed tests. This property is similar to Gradle's `AbstractTestTask.ignoreFailures` which is also `@Internal`
#KT-54787 Fixed

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/kotlin/org/jetbrains/kotlin/gradle/mpp/AggregatingKotlinTestReportIT.kt

@@ -98,7 +98,6 @@ class AggregatingKotlinTestReportIT : KGPBaseTest() {
 
     @DisplayName("Test tasks are up-to-date when called after `allTests`")
     @GradleTest
-    @Disabled
     fun testSuccessfulTestTasksAreUpToDate(gradleVersion: GradleVersion) {
         project(
             "new-mpp-lib-with-tests",

libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/tasks/KotlinTest.kt

@@ -51,7 +51,7 @@ abstract class KotlinTest : AbstractTestTask() {
 
     private val runListeners = mutableListOf<KotlinTestRunnerListener>()
 
-    @Input
+    @Internal
     var ignoreRunFailures: Boolean = false
 
     fun addRunListener(listener: KotlinTestRunnerListener) {