debugger: Change placeholder text for Custom/Run text input (#31264)

Before: 

![image](https://github.com/user-attachments/assets/6cdef5bb-c901-4954-a2ec-39c59f8314db)

After:

![image](https://github.com/user-attachments/assets/c4f60a23-249c-47ab-8a9e-a39e2277dd00)


Release Notes:

- N/A
f48b6b583ePiotr Osiewicz committed on 5/23/2025, 12:53:20 PM· committed by GitHubparentd8fc23a
1 file changedLine totals unavailable