bug: execution_order_group does not work with a folder without *.hcl files in the file structure

[SimonG-Alza]

Bug report

Using terragrunt-atlantis-config generate --output atlantis.yaml --create-workspace --create-project-name --execution-order-groups true in my terragrunt project, which contains folders without *.hcl files in the file structure.

To Reproduce

1. Download test_examples/terragrunt_dependency from https://github.com/transcend-io/terragrunt-atlantis-config/tree/master/test_examples/terragrunt_dependency.
2. Create file structure as:
   
3. Run terragrunt-atlantis-config generate --output atlantis.yaml --create-workspace --create-project-name --execution-order-groups true in test_examples

Doesn't work if you run terragrunt-atlantis-config generate --output atlantis.yaml --create-workspace --create-project-name --execution-order-groups true in test_examples/terragrunt_dependency and you nested the depender as in

Expected behavior

automerge: false
parallel_apply: true
parallel_plan: true
projects:
- autoplan:
    enabled: false
    when_modified:
    - '*.hcl'
    - '*.tf*'
  dir: dependency
  name: dependency
  workspace: dependency
- autoplan:
    enabled: false
    when_modified:
    - '*.hcl'
    - '*.tf*'
    - ../dependency/terragrunt.hcl
  dir: depender
  execution_order_group: 1 <-------- 
  name: depender
  workspace: depender
version: 3

Actual behavior

automerge: false
parallel_apply: true
parallel_plan: true
projects:
- autoplan:
    enabled: false
    when_modified:
    - '*.hcl'
    - '*.tf*'
  dir: terragrunt_dependency/dependency
  name: terragrunt_dependency_dependency
  workspace: terragrunt_dependency_dependency
- autoplan:
    enabled: false
    when_modified:
    - '*.hcl'
    - '*.tf*'
    - ../dependency/terragrunt.hcl
  dir: terragrunt_dependency/depender
  name: terragrunt_dependency_depender
  workspace: terragrunt_dependency_depender
version: 3

Relevant Terragrunt files
Using https://github.com/transcend-io/terragrunt-atlantis-config/tree/master/test_examples/terragrunt_dependency

Conclusion

terragrunt-atlantis-config generate --output atlantis.yaml --create-workspace --create-project-name --execution-order-groups true iterates through 2 levels of subdirectories (if all of them contains *.hcl) from the current path, but not whole project.