Mark all Worker-related API as obsolete.

* Explain what obsolete means and why workers are obsolete
* Add some documentation to workers to explain its common pitfalls

^KT-54702


Merge-request: KT-MR-9563
Merged-by: Vsevolod Tolstopyatov <qwwdfsad@gmail.com>

kotlin-native/backend.native/tests/interop/objc/illegal_sharing.kt

@@ -1,4 +1,4 @@
-@file:OptIn(FreezingIsDeprecated::class)
+@file:OptIn(FreezingIsDeprecated::class, ObsoleteWorkersApi::class)
 
 import kotlin.native.concurrent.*
 import kotlin.test.*

kotlin-native/backend.native/tests/interop/objc/illegal_sharing_with_weak/main.kt

@@ -1,3 +1,4 @@
+@file:OptIn(ObsoleteWorkersApi::class)
 import kotlin.native.concurrent.*
 import kotlinx.cinterop.autoreleasepool
 import objclib.*

kotlin-native/backend.native/tests/interop/objc/kt42172/main.kt

@@ -1,4 +1,4 @@
-@file:OptIn(kotlin.native.runtime.NativeRuntimeApi::class)
+@file:OptIn(kotlin.native.runtime.NativeRuntimeApi::class, ObsoleteWorkersApi::class
 
 import objclib.*
 import kotlin.native.concurrent.*

kotlin-native/backend.native/tests/interop/objc/tests/objcWeakRefs.kt

@@ -1,4 +1,4 @@
-@file:OptIn(FreezingIsDeprecated::class, kotlin.native.runtime.NativeRuntimeApi::class)
+@file:OptIn(FreezingIsDeprecated::class, kotlin.native.runtime.NativeRuntimeApi::class, ObsoleteWorkersApi::class)
 
 import kotlinx.cinterop.*
 import kotlin.native.concurrent.*

kotlin-native/backend.native/tests/interop/objc/tests/sharing.kt

@@ -1,4 +1,4 @@
-@file:OptIn(FreezingIsDeprecated::class)
+@file:OptIn(FreezingIsDeprecated::class, ObsoleteWorkersApi::class)
 
 import kotlinx.cinterop.*
 import kotlin.native.concurrent.*

kotlin-native/backend.native/tests/interop/objc/tests/utils.kt

@@ -1,4 +1,4 @@
-@file:OptIn(FreezingIsDeprecated::class)
+@file:OptIn(FreezingIsDeprecated::class, ObsoleteWorkersApi::class)
 
 import kotlinx.cinterop.*
 import kotlin.native.concurrent.*
@@ -16,4 +16,4 @@ fun nsArrayOf(vararg elements: Any): NSArray = NSMutableArray().apply {
     elements.forEach {
         this.addObject(it as ObjCObject)
     }
-}
+}

kotlin-native/backend.native/tests/interop/objc/tests/workerAutoreleasePool.kt

@@ -1,4 +1,4 @@
-@file:OptIn(FreezingIsDeprecated::class)
+@file:OptIn(FreezingIsDeprecated::class, ObsoleteWorkersApi::class)
 
 import kotlin.native.concurrent.*
 import kotlinx.cinterop.*