Removed unused props in the avatar link components

What does this MR do?

In assignee_avatar_link, we were passing the same props down as the scoped slot value. It didnt seem necessary so I removed it. We were also not using rootPath prop, so i removed that as well.

Screenshots

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• [-] Database guides
• [-] Separation of EE specific content