"exclude must be a string." error using mbxDirections in mapbox-sdk-js 13.3

Nobody has claimed this yet.

Our team has been using `mbxDirections` to calculate road distance using Mapbox for ~2 months with the following configs.
```
await directionsService
.getDirections({
profile: 'driving',
waypoints: stops.map((s) => ({
coordinates: [s.longitude, s.latitude],
})) as DirectionsWaypoint[],
geometries: 'polyline',
overview: 'full',
steps: true,
exclude: ['ferry'],
})
.send();
```

However, our API stopped working and started seeing `Error: exclude must be a string.` since 7/12/22.
I tried updating to the latest (13.4) of the sdk, and the same issue still remains.
I tried removing the sdk and instead querying the endpoint directly with the following CURL and it works
```
curl --location --request GET 'https://api.mapbox.com/directions/v5/mapbox/driving/-122.393806%2C37.786041%3B-122.401527%2C37.788712?geometries=polyline&overview=full&steps=true&exclude=ferry&access_token=
```

I would like to confirm with mapbox that this is due to an API change that isn't being reflected in the sdk client. Thank you!

Start at the mbxDirections directionsService.getDirections(...).send() request path and inspect how the exclude option is serialized. Compare the SDK request with the working curl example, then verify that the resulting request accepts the documented ferry exclusion and add or run coverage for this configuration.

Written by the indexing model from the issue text.