* build: remove auth for go mod download
- Not needed now that all module deps are public.
* mark generated ci config as generated
* build: no GOPRIVATE needed
* packagespec: remove meta.POST_PROCESSORS
- This is no longer needed in the spec file, as post-processor
definitions are now standardized and not project-specific,
as of Packagespec v0.1.4
* build: include go.{mod,sum} from go submodules