Make work with worker

[mrloop]

I'm using dynamodb-localhost in vitest, it uses worker threads and as suggested vitest-dev/vitest#1544 a check is required when spawning

Otherwise you get an error similar to

TypeError [ERR_INVALID_ARG_VALUE]: The argument 'stdio' is invalid. Received WritableWorkerStdio {
  _writableState: WritableState {
    objectMode: false,
    highWaterMark: 16384,
    finalCalled: false,...