Fix pinned tab becoming unpinned when dragged onto unpinned tab (#35539)

Case A - Correct:


https://github.com/user-attachments/assets/2ab943ea-ca5b-4b6b-a8ca-a0b02072293e

Case B - Incorrect:


https://github.com/user-attachments/assets/912be46a-73b2-48a8-b490-277a1e89d17d

Case B - Fixed:


https://github.com/user-attachments/assets/98c2311d-eebc-4091-ad7a-6cf857fda9c3

Release Notes:

- Fixed a bug where dragging a pinned tab onto an unpinned tab wouldn't
decrease the pinned tab count
4417bfe30bJoseph T. Lyons committed on 8/3/2025, 5:56:33 AM· committed by GitHubparent986e3e7
1 file changedLine totals unavailable