expand support for Snyk IaC linting

@snyk [recently](https://github.com/snyk/actions/commit/fa1c57858888040b3de7dc7516908550556d7835) (~ 5 months) updated the [Snyk IaC](https://github.com/snyk/actions/tree/master/iac) Action to support passing in directory references (vs. explicitly defining each `.tf` file on a single line).

This means that it is now feasible to enable Snyk IaC for _all_ repositories in @workloads.