Fix date-fns import that pulls in entire library in consuming apps

[acorncom]

I recently bumped date-fns up to v4 for a client and upgraded to 3.2.0 of this library as well. In the process, the entire date-fns library started getting pulled in, although we'd very carefully worked to ensure we were importing just the pieces we needed (and had made sure that was working).

It took a bit of digging, but it turns out the addition of the getDefaultOptions import as part of the 3.2.0 upgrade led to the entire date-fns library getting pulled in, as the import from the main barrel file of date-fns then means that consumers can't tree-shake properly.

This two-line patch gets this app's bundle size back where we expected.

Thanks for your work on this library over the years, it's been much appreciated!