Integrate dayjs locales into custom library

Hi there,

currently we are developing a library which should provide us the opportunity to encapsulate all date and theme specific parts.
This is the specific part in the library code. The LocalizationProvider is a material-ui component.
```
const translateLocale = (): string | undefined => {
if (locale.startsWith('en'))
return 'en'
if (locale.startsWith('de'))
return 'de'
if (locale.startsWith('cs'))
return 'cs'
}

{children}

```

But unfortunately we have to import the dayjs locales in all projects that are using our library. Currently it is not possible to import the locales in the library.
```
import 'dayjs/locale/de'
import 'dayjs/locale/en'
import 'dayjs/locale/cs'
```

Is there any way to integrate the dayjs library/locales with rollup into the library in such a way, that we don't have to import locales in projects that are using our library?

Thank you a lot,

Simon

Start by reviewing the Rollup configuration and the dayjs locale imports shown in the issue, along with how LocalizationProvider passes adapterLocale. Determine whether the package can include these locales without consumer imports, and verify that the supported en, de, and cs locales work from consuming projects.

Written by the indexing model from the issue text.