(reopening) Unsupported macOS container/docker action error message

[joeycumines]

Opening a new issue as I cannot reopen #715 - it appears to have regressed. I've confirmed the error is present for all of the non-linux platforms available to public repositories via GitHub hosted runners.

Describe the bug

When running a workflow on macOS if you use a container/docker action you receive an error message that doesn't describe the fact that container/docker action aren't supported on macOS.

Error: Value cannot be null. (Parameter 'container')

It would be ✨ if this message could be improved.

To Reproduce

Steps to reproduce the behavior:

1. Create a workflow that targets macOS
2. Use a container/docker action
3. See error Error: Value cannot be null. (Parameter 'container')

Expected behavior

An error message that describes that container/docker action aren't supported on macOS would be nice.

Runner Version and Platform

Latest/Hosted runner on macOS

Job Log Output

An example of the error can be seen here https://github.com/automationcloud/autopilot/runs/1143430926?check_suite_focus=true