[umami] fix build error

[ghost]

Fixing build SWC build error: https://nextjs.org/docs/messages/failed-loading-swc

[noave]

If the build process fails with a "Failed to load SWC binary" you need a .babelrc file in your umami directory with the following content {"presets": ["next/babel"]}

this pretty much sounds like the guide itself has to be updated, not like this only happens sometimes?

BTW, please follow the guideline for commit messages: https://github.com/Uberspace/lab/blob/main/STYLE.md#add-your-changes-to-the-uberspace-lab