debugger: Disambiguate child session labels (#31526)

Add `(child)` instead of using the same label.

Release Notes:

- Debugger Beta: Made child sessions appear distinct from their parents
in the session selector.
384b11392aCole Miller committed on 5/29/2025, 1:44:15 AM· committed by GitHubparentf20596c
1 file changedLine totals unavailable