Hcl Validate Dependency Outputs

hcl validate no longer fails on dependency.outputs references

terragrunt hcl validate previously failed with "Unsupported attribute" when a configuration referenced dependency.<name>.outputs.<key> without mock_outputs.

During validation, output resolution is skipped, but the outputs attribute was never added to the dependency evaluation context, causing any output reference to error. The fix provides a dynamic placeholder for dependency outputs (and inputs) during validation so that attribute access evaluates to unknown rather than failing. Additionally, the dependency resolution pipeline is now more resilient during validation. Dependencies with unresolvable config_path values or nonexistent targets no longer cause the entire dependency namespace to disappear from the evaluation context.