[Gradle] Mark KotlinTopLevelExtension.useCompilerVersion as experimental

#KT-61895 Fixed

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

@@ -12,6 +12,7 @@ import org.gradle.api.Project
 import org.gradle.api.internal.plugins.DslObject
 import org.gradle.jvm.toolchain.JavaLanguageVersion
 import org.gradle.jvm.toolchain.JavaToolchainSpec
+import org.jetbrains.kotlin.buildtools.api.ExperimentalBuildToolsApi
 import org.jetbrains.kotlin.gradle.ExperimentalKotlinGradlePluginApi
 import org.jetbrains.kotlin.gradle.internal.KOTLIN_BUILD_TOOLS_API_IMPL
 import org.jetbrains.kotlin.gradle.internal.KOTLIN_MODULE_GROUP
@@ -142,6 +143,8 @@ abstract class KotlinTopLevelExtension(internal val project: Project) : KotlinTo
      *
      * Currently only has an effect if the `kotlin.compiler.runViaBuildToolsApi` Gradle property is set to `true`.
      */
+    @ExperimentalKotlinGradlePluginApi
+    @ExperimentalBuildToolsApi
     fun useCompilerVersion(version: String) {
         project.dependencies.add(BUILD_TOOLS_API_CLASSPATH_CONFIGURATION_NAME, "$KOTLIN_MODULE_GROUP:$KOTLIN_BUILD_TOOLS_API_IMPL:$version")
     }