Well that's the whole idea about Vapor, because it runs in a Lambda on AWS. They have limits and should keep to them otherwise the lambda's wouldn't make any sense!
So it's probably wise to remove all files from your application that you don't need to run your application. For example data files that you use in tests or the node_modules directory and so on.
if you have a large collection of public assets (images and files in the public folder) then you should consider moving these to a seperate location like a CDN. They are probably only referenced by URL (not code) and that URL could point anywhere.