Revert "fix: not multithread safe access to cancel var"

This reverts commit 3184f84.

Author: abelonogov-ld

LaunchDarkly/LaunchDarkly/LDClient.swift

@@ -385,29 +385,20 @@ public class LDClient {
             os_log("%s LDClient.identify was called with a timeout greater than %f seconds. We recommend a timeout of less than %f seconds.", log: config.logger, type: .info, self.typeName(and: #function), LDClient.longTimeoutInterval, LDClient.longTimeoutInterval)
         }
 
-        // Use a thread-safe way to handle cancellation/completion state
-        let completionQueue = DispatchQueue(label: "com.launchdarkly.ldclient.identify-completion", attributes: .concurrent)
-        var completed = false
-
-        let finish: (IdentifyResult) -> Void = { result in
-            var shouldCall = false
-            completionQueue.sync(flags: .barrier) {
-                if !completed {
-                    completed = true
-                    shouldCall = true
-                }
-            }
-            if shouldCall {
-                completion(result)
-            }
-        }
+        var cancel = false
 
         DispatchQueue.global().asyncAfter(deadline: .now() + timeout) {
-            finish(.timeout)
+            guard !cancel else { return }
+
+            cancel = true
+            completion(.timeout)
         }
 
         identify(context: context, useCache: useCache) { result in
-            finish(result)
+            guard !cancel else { return }
+
+            cancel = true
+            completion(result)
         }
     }