Refactor Cache locking mechanism to use NSRecursiveLock for improved thread safety and prevent deadlocks. Added comprehensive thread safety tests to validate the fix and ensure no new locking issues are introduced.

Sources/Cache/Cache/Cache.swift

@@ -16,7 +16,8 @@ import Foundation
 open class Cache<Key: Hashable, Value>: Cacheable, @unchecked Sendable {
 
     /// Lock to synchronize the access to the cache dictionary.
-    fileprivate var lock: NSLock
+    /// Using NSRecursiveLock to prevent re-entrant lock deadlocks with @Published property wrapper
+    fileprivate var lock: NSRecursiveLock
 
     #if os(Linux) || os(Windows)
     fileprivate var cache: [Key: Value] = [:]
@@ -31,7 +32,7 @@ open class Cache<Key: Hashable, Value>: Cacheable, @unchecked Sendable {
      - Parameter initialValues: An optional dictionary of initial key-value pairs.
      */
     required public init(initialValues: [Key: Value] = [:]) {
-        lock = NSLock()
+        lock = NSRecursiveLock()
         cache = initialValues
     }