fix: replace dropdown in project cards in Op Dashboard with icon

What does this MR do?

The operations dashboard contains one to many project cards, which have a drop-down icon on the right:

There should only be one icon for the only action available, which is to remove the project from the dashboard. This is what it looks like now:

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation created/updated or follow-up review issue created
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Closes #11716 (closed)