Don't set attachments path if no file I/O

Author: grynspan

Sources/Testing/Running/Runner.swift

@@ -369,9 +369,11 @@ extension Runner {
   private static func _run(_ runner: Self) async {
     var runner = runner
     runner.configureEventHandlerRuntimeState()
+#if !SWT_NO_FILE_IO
     if let attachmentDirectoryPath = runner.configuration.attachmentDirectoryPath {
       runner.configureToWriteAttachments(toDirectoryAtPath: attachmentDirectoryPath)
     }
+#endif
 
     // Track whether or not any issues were recorded across the entire run.
     let issueRecorded = Locked(rawValue: false)