managing static dependencies

Hi all - I hope everyone is keeping well.

I would like to replace all the javascript (&css) libs in my project that are currently pointing to internet cdn locations with downloaded copies so I could run my project on a standalone network. I’d like to consolidate and use an up to date version of the library. node and yarn equivalents.

Is there a good library out there for this? Or is there a way to structure my project so that I have a single static folder that is like a node environment?