Add automation to check for un-labelled resources

[NimJay]

• Problem: As we were working on a Jump Start Solution, we realized that we forgot to label the resources using the "labels" variable.
• See this Google-internal doc. This document states that all Blueprint resources should set the "labels" argument (where applicable) to "var.labels".
• Ideally, we would either:
  • have automation that adds these labels in any Terraform resource that supports the "label" argument.
  • have automation that warns developers that Terraform resource that
• Feature request: Would it be possible to add a check inside the lint GitHub Action that warns users about unlabelled resources (for resources that support the "labels" arg)?

Additional info

• This is a nice-to-have. Feel free to close. :)
• Here's the issue where we realized that we forgot to label resources: Add labels variable and label resources terraform-genai-knowledge-base#94.

[bharathkkb]

Thanks for the suggestion @NimJay! This is definitely something on our radar - a potential implementation path is via tflint #1453 which runs as part of our lint workflow