[DevTools] Don't show "awaited by" if there's nothing to show (#34163)

E.g. if the owner is null or the same as current component and no stack.
This happens for example when you return a plain Promise in the child
position and inspect the component it was returned in since there's no
hook stack and the owner is the same as the instance itself so there's
nothing new to link to.

Before:

<img width="267" height="99" alt="Screenshot 2025-08-10 at 10 28 32 PM"
src="https://github.com/user-attachments/assets/23341ab2-2888-457d-a1d1-128f3e0bd5ec"
/>

After:

<img width="253" height="91" alt="Screenshot 2025-08-10 at 10 29 04 PM"
src="https://github.com/user-attachments/assets/b33bb38b-891a-4f46-bc16-15604b033cdb"
/>