fix: Dynamo compile support for None outputs

[dongwoonhyun]

Description

Currently, any model outputs that are None literals (e.g., auxiliary outputs) cause a compile crash when trying to access the attribute target.

This PR adds a continue if is None, and adds a simple test.

Type of change

• Bug fix (non-breaking change which fixes an issue)

Checklist:

• My code follows the style guidelines of this project (You can use the linters)
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas and hacks
• I have made corresponding changes to the documentation
• I have added tests to verify my fix or my feature
• New and existing unit tests pass locally with my changes
• I have added the relevant labels to my PR in so that relevant reviewers are notified