workspace: Add right border to pinned tabs only on scroll (#29405)

Before (scrolled state, bug):
<img width="392" alt="before - with scroll"
src="https://github.com/user-attachments/assets/5f62f050-41e0-4740-8f90-9822348eaa4b"
/>

After (scrolled state, bug fixed):
<img width="344" alt="after - with scroll"
src="https://github.com/user-attachments/assets/33003358-0009-4748-8a6e-642158114b82"
/>

Before (without scrolled state, as it is):
<img width="541" alt="before - without scroll"
src="https://github.com/user-attachments/assets/42487d61-7f7c-49a7-a087-da7faf5a0a89"
/>

After (without scrolled state, as it is):
<img width="462" alt="after - without scroll"
src="https://github.com/user-attachments/assets/738a4d24-3a89-466b-8976-2bf47cfeb0f5"
/>

cc @danilo-leal 

Release Notes:

- N/A
357e38b471Smit Barmase committed on 4/25/2025, 1:16:13 PM· committed by GitHubparentae37f3c
1 file changedLine totals unavailable