Add option to use default files for label actions

### 📝 Description of the feature

The labeler and label-syncer actions could incorporate an input to use default `label.yml` and `labeler.yml` files stored in the `ansys/actions` repository

Thanks @ansjhenry for this suggestion!

### 💡 Steps for implementing the feature

- Check if the user wants to use the default `label.yml` or `labeler.yml` file provided in the `ansys/actions` repo
- If so, retrieve the file from the actions repo. If not, use the file in their existing repo

### 🔗 Useful links and references

[Wrapper for labeler action](https://github.com/ansys-internal/scade-ext-workflow/tree/main/_labeler)
[Wrapper for label-sync action](https://github.com/ansys-internal/scade-ext-workflow/tree/main/_label-syncer)

Start with the linked _labeler and _label-syncer wrappers and trace how each currently chooses label.yml or labeler.yml. Check how an opt-in default-file choice could retrieve files from ansys/actions while preserving the existing repository-file path. Done means both wrappers support the choice without changing current behavior when it is not enabled.

Written by the indexing model from the issue text.