wasm file was always download from the network

[Gaubee]

if use import { build } from "https://deno.land/x/dnt/mod.ts";
the wasm file's url will be https://deno.land/x/dnt/lib/pkg/dnt_wasm_bg.wasm.

https://github.com/denoland/dnt/blob/main/lib/pkg/dnt_wasm.generated.js#L635
it will run fetch(wasmUrl), without import from local:

for now I have to download the dnt source code and run it locally to avoid having to download wasm from the network every time I start up. This greatly improves startup efficiency. but I wish there was a better way.

[dsherret]

I need to land denoland/wasmbuild#68