Scheme code coverage targets can reference targets in other projects, including SPM packages

Project schemes can now declare code coverage targets that live in a different project of the workspace, including targets coming from generated Swift Package Manager projects, by using an explicit TargetReference(projectPath:target:). Previously tuist generate failed during project linting when a scheme’s “Gather coverage for” list referenced a target that was not defined in the same project, even though Xcode accepts that configuration. Local target references are still validated (typo detection is preserved), invalid references are still caught by the workspace-level graph linter, and behavior for targets inside the same project is unchanged.