file_finder: Fix right border not rendering (#35684)

Closes #35683

Release Notes:

- Fixed file finder borders not rendering properly

Before: 

<img width="1921" height="1081" alt="image"
src="https://github.com/user-attachments/assets/62f39bfb-3e0e-43af-a00a-a6c378b067fc"
/>

After:

<img width="1921" height="1081" alt="image"
src="https://github.com/user-attachments/assets/b9a00e4c-c126-40a4-9a63-8e44396a0e84"
/>
f3399daf6cAlvaro Parker committed on 8/8/2025, 9:32:13 PM· committed by GitHubparent2be6f9d
1 file changedLine totals unavailable