fix: #8686 prevent useGridCell from overriding child focus restoration loops

[jsmitrah]

Closes #8686

✅ 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:

• Tab into the table row and use the arrow keys to focus on the "Open Dialog" button.
• Press Enter to open the modal dialog, then press Escape to close it.
• Verify that focus returns exactly to the "Open Dialog" button instead of jumping to the "Action 1" button.

🧢 Your Project:

[snowystinger]

Thanks for the interest, if you run yarn format it should get rid of all the noisy whitespace changes that I'm guessing your IDE applied

[jsmitrah]

Thanks @snowystinger, all tests are passed

[snowystinger]

This seems like an important comment. JSDOM and the act environment is not a reliable test against this as it's simulating real browsers.
Did you run this against real browsers? If I recall, document.activeElement can be updated at different times depending on the browser you're in as well.

[jsmitrah]

Good catch, @snowystinger. To avoid the timing issues of the document.activeElement across different real browsers, I updated the approach to use e.relatedTarget.

By checking e.relatedTarget synchronously, we can instantly determine if focus is moving directly into a nested child element. This provides identical, reliable accuracy in both JSDOM and real browsers without needing to wait for a frame

I've pushed the update.