Add annotations due to upgraded Kotlin

Author: dkhalanskyjb

core/nix/src/TimeZoneNative.kt

@@ -2,6 +2,7 @@
  * Copyright 2019-2023 JetBrains s.r.o. and contributors.
  * Use of this source code is governed by the Apache 2.0 License that can be found in the LICENSE.txt file.
  */
+@file:OptIn(kotlinx.cinterop.ExperimentalForeignApi::class)
 
 package kotlinx.datetime
 

core/nix/src/internal/filesystem.kt

@@ -3,7 +3,7 @@
  * Use of this source code is governed by the Apache 2.0 License that can be found in the LICENSE.txt file.
  */
 
-@file:OptIn(ExperimentalForeignApi::class)
+@file:OptIn(kotlinx.cinterop.ExperimentalForeignApi::class)
 package kotlinx.datetime.internal
 
 import kotlinx.cinterop.*