[rush] Remove unnecessary decouple checks

[L-Qun]

Summary

- if (localProject && !this.decoupledLocalDependencies.has(dependency)) {
+ if (localProject) {

I think this logic is redundant because if we haven't declared a package in decoupledLocalDependencies and the package is a local project, it must be dependent in a workspace manner.

[iclanton]

This check is actually necessary. There are two scenarios where this will cause a problem. 1 - a non-workspaces repo and 2 - a case where you specify a range that is satisfiable by the local version of the package, but you explicitly want a published copy.