[K/N] Deprecated freezing ^KT-50541

Starting with 1.7.20 freezing is deprecated. See https://github.com/JetBrains/kotlin/blob/master/kotlin-native/NEW_MM.md#freezing-deprecation for details.

Merge-request: KT-MR-6399
Merged-by: Alexander Shabalin <Alexander.Shabalin@jetbrains.com>

kotlin-native/backend.native/tests/objcexport/values.kt

@@ -5,6 +5,7 @@
 
 // All classes and methods should be used in tests
 @file:Suppress("UNUSED")
+@file:OptIn(FreezingIsDeprecated::class)
 
 package conversions
 
@@ -856,8 +857,11 @@ class SharedRefs {
         mutableListOf()
     }
 
+    @OptIn(FreezingIsDeprecated::class)
     fun createFrozenRegularObject() = createRegularObject().freeze()
+    @OptIn(FreezingIsDeprecated::class)
     fun createFrozenLambda() = createLambda().freeze()
+    @OptIn(FreezingIsDeprecated::class)
     fun createFrozenCollection() = createCollection().freeze()
 
     fun hasAliveObjects(): Boolean {