[SE-0329] Update the Task.sleep(for:) method (#60473)

(cherry picked from commit 624124d)

Co-authored-by: Ben Rimmington <[email protected]>

Author: Catfish-Man

stdlib/public/Concurrency/TaskSleepDuration.swift

@@ -142,4 +142,20 @@ extension Task where Success == Never, Failure == Never {
   ) async throws {
     try await clock.sleep(until: deadline, tolerance: tolerance)
   }
+  
+  /// Suspends the current task for the given duration on a continuous clock.
+  ///
+  /// If the task is cancelled before the time ends, this function throws 
+  /// `CancellationError`.
+  ///
+  /// This function doesn't block the underlying thread.
+  ///
+  ///       try await Task.sleep(for: .seconds(3))
+  ///
+  /// - Parameter duration: The duration to wait.
+  @available(SwiftStdlib 5.7, *)
+  @_alwaysEmitIntoClient
+  public static func sleep(for duration: Duration) async throws {
+    try await sleep(until: .now + duration, clock: .continuous)
+  }
 }