[Gradle] Remove unnecessary useK2 gradle property

^KT-64379 Verification Pending

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

@@ -174,9 +174,6 @@ internal class PropertiesProvider private constructor(private val project: Proje
     val useKotlinAbiSnapshot: Boolean
         get() = booleanProperty(KOTLIN_ABI_SNAPSHOT) ?: false
 
-    val useK2: Boolean?
-        get() = booleanProperty("kotlin.useK2")
-
     val keepMppDependenciesIntactInPoms: Boolean?
         get() = booleanProperty("kotlin.mpp.keepMppDependenciesIntactInPoms")
 

libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/compilationImpl/KotlinCreateNativeCompileTasksSideEffect.kt

@@ -40,9 +40,6 @@ internal val KotlinCreateNativeCompileTasksSideEffect = KotlinCompilationSideEff
         task.enabled = compilation.konanTarget.enabledOnCurrentHost
 
         task.destinationDirectory.set(project.klibOutputDirectory(compilationInfo).dir("klib"))
-        if (project.kotlinPropertiesProvider.useK2 == true) {
-            task.compilerOptions.useK2.set(true)
-        }
         task.runViaBuildToolsApi.value(false).disallowChanges() // K/N is not yet supported
 
         task.explicitApiMode.value(

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

@@ -85,10 +85,6 @@ internal abstract class AbstractKotlinCompileConfig<TASK : AbstractKotlinCompile
 
             task.incremental = false
             task.useModuleDetection.convention(false)
-            if (propertiesProvider.useK2 == true) {
-                @Suppress("DEPRECATION")
-                task.compilerOptions.useK2.value(true)
-            }
             task.runViaBuildToolsApi.convention(propertiesProvider.runKotlinCompilerViaBuildToolsApi).finalizeValueOnRead()
             task.classLoadersCachingService.value(cachedClassLoadersService).disallowChanges()