Unreleased packages should still trigger dependent releases

[saiichihashimoto]

If the dependency of packages is A depends on B depends on C, then a change in C triggers a release in A & B, which is good. The issue is if C isn't a package that gets released, eg it's a private package and we use --ignore-private-packages. I don't want to release it, but I still want changes in C to trigger a release in A & B. The list of packages that get released and the list of packages that could trigger a new release shouldn't necessarily be one-to-one. As of now, I'm forced to release C just so A & B are updated.

[saiichihashimoto]

As an example, my monorepo has a @scope/tsconfig package and other internal packages that aren't intended to be released, but are used by other packages that are released. If I update any of the internal packages in a patch, minor, or major way, the external packages should definitely trigger a semantic release.