JS - Issue with Config on Recent Release - "d2lang error cannot read properties of undefined (reading 'exports')"

https://alixander-d2js.web.val.run/

```
a
a -> b


vars: { 
  d2-config: {
    # layout-engine: elk # Doesn't work
    layout-engine: dagre # Works
  } 
} 

```

Something has gone a bit haywire in the last day or two. 

From the testing I've been doing, seems to be specific to elk layout engine, dagre works fine. 

cc. @alixander 