Cloning shared board doubles own user in the user list

[bentuna]

Describe the bug
When you clone a board that was shared with you, your user appears double in the sidebar under "Sharing".

To Reproduce
Steps to reproduce the behavior:

1. User A shares a board with user B.
2. User B clones the board.
3. User B opens the board details of the board copy and sees the issue.

Expected behavior
User B should be the owner of the copy and sole user in the list of users.

Nextcloud version: 31.0.12

Deck version: 1.15.6