Add support for Node v18, v20 and v22

[vikiv480]

The supported Node LTS versions is v18, v20 and v22. The following specs are failing when the Node version is updated:

~/repos/twingly-search-api-node
❯ node --version
v18.20.5
~/repos/twingly-search-api-node
❯ npm test

> twingly-search@1.1.1 test
> ./node_modules/.bin/mocha

  1) Client
       #executeQuery()
         with invalid api key
           should throw error:
     Uncaught TypeError [ERR_INVALID_ARG_TYPE]: The "stream" argument must be an instance of ReadableStream, WritableStream, or Stream. Received an instance of EventEmitter
      at eos (node:internal/streams/end-of-stream:73:11)
      at IncomingMessage._destroy (node:_http_incoming:231:21)
      at _destroy (node:internal/streams/destroy:122:10)
      at IncomingMessage.destroy (node:internal/streams/destroy:84:5)
      at endReadableNT (node:internal/streams/readable:1714:16)
      at process.processTicksAndRejections (node:internal/process/task_queues:90:21)
      
  2) Query
       #execute()
         when searching for spotify
           should get posts:
     Uncaught TypeError [ERR_INVALID_ARG_TYPE]: The "stream" argument must be an instance of ReadableStream, WritableStream, or Stream. Received an instance of EventEmitter
      at eos (node:internal/streams/end-of-stream:73:11)
      at IncomingMessage._destroy (node:_http_incoming:231:21)
      at _destroy (node:internal/streams/destroy:122:10)
      at IncomingMessage.destroy (node:internal/streams/destroy:84:5)
      at endReadableNT (node:internal/streams/readable:1714:16)
      at process.processTicksAndRejections (node:internal/process/task_queues:90:21)