Remove unused haml file

What does this MR do?

Remove unused haml file app/views/groups/_shared_projects.html.haml that was last modified over a year ago. Found this file while reviewing https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/12834

Are there points in the code the reviewer needs to double check?

Double check that this haml file is truly orphaned

Why was this MR needed?

Remove unused code

Screenshots (if relevant)

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• API support added
• Tests
  • Added for this feature/bug
  • All builds are passing
• Conform by the merge request performance guides
• Conform by the style guides
• Branch has no merge conflicts with master (if it does - rebase it please)
• Squashed related commits together

What are the relevant issue numbers?

#35044 (closed)