Fix CI: use withLock instead of rawValue for cross-platform compatibility

Author: tienquocbui

Sources/Testing/Events/Recorder/Event.HumanReadableOutputRecorder.swift

@@ -940,8 +940,8 @@ extension Event.HumanReadableOutputRecorder {
   /// - Returns: A formatted string containing the failure summary, or `nil`
   ///   if there were no failures.
   func generateFailureSummary(options: Event.ConsoleOutputRecorder.Options) -> String? {
-    let context = _context.rawValue
-    let summary = Event.TestRunSummary(from: context.testData)
+    let testData = _context.withLock { $0.testData }
+    let summary = Event.TestRunSummary(from: testData)
     return summary.formatted(with: options)
   }
 }