withoutEnlargement

Hi! Could you please help me to add this sharp option (https://sharp.pixelplumbing.com/api-resize#parameters):
_options.withoutEnlargement Boolean do not enlarge if the width or height are already less than the specified dimensions, equivalent to GraphicsMagick's > geometry option. (optional, default false)_

Is it possible?
I have tried different variants that are not working:
```
.pipe(sharpResponsive({
includeOriginalFile: true,
withoutEnlargement: true,
formats: [
{ width: 768, sharp: { withoutEnlargement: true }, withoutEnlargement: true, quality: 100, rename: { suffix: "_mq2" } },
]
}))
```
The original image (3kb) is enlarged to 1202kb

Start at the sharpResponsive option handling and trace how resize options are passed to Sharp. Compare the requested withoutEnlargement behavior with Sharp's resize parameters, then verify using the supplied 3kb image and 768px width that the output is not enlarged.

Written by the indexing model from the issue text.