Can't use local env vars in template strings in workflow steps

[eysi09]

Bug

Current Behavior

I'm getting a validation error when using local env vars in workflow steps, see repro below.

Reproducible example

Create a workflow like this:

kind: Workflow
name: run-tests
steps:
  - name: run-tests
    skip: ${local.env.SKIP != ''}
    command: [test]

Run garden validate and observe the error:

Error validating workflow: key .steps[0][skip] must be a boolean

Workaround

This only seems to be an issue with local env vars so the following should work:

kind: Project
variables:
  skip: ${local.env.SKIP}

---

kind: Workflow
name: run-tests
steps:
  - name: run-tests
    skip: ${var.SKIP != ''}
    command: [test]

Suggested solution(s)

Additional context

This was written in a hurry, @thsig feel free to elaborate.

Your environment

• OS:
• How I'm running Kubernetes:

garden version