[rush] Fix edge cases where Rush does not update the lockfile

[L-Qun]

Details

If the user moves a package from dependencies to devDependencies, and then runs rush update, Rush should update the lockfile correctly, but it does not. This issue occurs because it triggers case DependencyType.Dev, but Rush cannot find this package in importer.devDependencies. Consequently, Rush deletes it from the importerDependencies set.

Impacted documentation

None.