Configure sst-env.d.ts generation

[oscartbeaumont]

It would be great to be able to disable the generation of sst-env.d.ts for a specific package or a group of packages mostly likely by having a configurable exclude pattern.

For example my monorepo at it's root has:

• sst.config.ts
• packages/*
• apps/*

By the current SST logic everything in packages/* gets given an sst-env.d.ts even though I would rather it not have one.

In practice I don't want anything in packages directly touching the infrastructure as they are designed to be self-contained packages such as what would potentially be publishable to npm. Not having the types helps to force separatation and cleans up the Git diff everytime a resource with links is changed in SST.

Broken out from my comment in #1017.

[paolostyle]

We have the same problem. What would be even better if SST was somehow able to generate sst-env.d.ts tailored for each package (I guess based on handler paths and their links? I can imagine it's quite tricky to do it right) - it's pretty annoying that every change in SST config results in like 20 changed files even though it realistically only affects one of packages.