chore: limit labeler false positives

[snowystinger]

Closes

This should only match if we change source files really, maybe css or some others, but if it's just stories or tests, then I'm not sure we need the labeler

✅ Pull Request Checklist:

• Included link to corresponding React Spectrum GitHub Issue.
• Added/updated unit tests and storybook for this change (for new code or code which already has tests).
• Filled out test instructions.
• Updated documentation (if it already exists for this component).
• Looked at the Accessibility Practices for this feature - Aria Practices

📝 Test Instructions:

🧢 Your Project:

[yihuiliao]

seems reasonable to me!