`tsBuildInfoFile` is supposed to be relative to `tsconfig` like `outDir`
is.
Because of this, we are currently saving the TS incremental build cache
for all packages in the same file. This is likely causing issues where
the built backend code sometimes does not accurately map to the current
source code.
This PR changes the incremental build setup to keep the cache in
individual `dist` folders, like it used to be up until a 2 months ago,
before https://github.com/n8n-io/n8n/pull/6816.
