Handle case where object expression has spread element without keys

[TobbenTM]

Small patch to avoid getting errors when seeing object expressions containing spread elements without keys like these:

{
  "type": "ObjectExpression",
  "properties": [
    {
      "type": "SpreadElement",
      "argument": {
        "type": "Identifier",
        "name": "props"
      }
    }
  ]
}

As far as I understand the code here, skipping any properties without a key should be totally fine, but let me know if we need to do some extra work to identify them.

[TobbenTM]

To add some context @bradlc , if trying to update the packages of the Tailwind UI Protocol template to the latest Next.js, MDX loaders, etc, then this error will occur. Any chance we can get this quick fix merged and released? It's blocking my upgrade path at the moment 😅

[bradlc]

Thanks!