@babel/plugin-proposal-private-property-in-object dependency not declared explicitely

[johanneskastl]

Just saw this during building. Not critical, but might be good idea to fix it.

[   30s] Creating an optimized production build...
[   35s] One of your dependencies, babel-preset-react-app, is importing the                              
[   35s] "@babel/plugin-proposal-private-property-in-object" package without                             
[   35s] declaring it in its dependencies. This is currently working because                             
[   35s] "@babel/plugin-proposal-private-property-in-object" is already in your                          
[   35s] node_modules folder for unrelated reasons, but it may break at any time.

[joaquimrocha]

We rely on create-react-app which has been inactive for a while. I think these are related.
We are looking for moving away from CRA. Hopefully it happens soon.