Remove link icon from file gutter

What does this MR do and why?

• Removes the link icon from file gutters

Why?

• The line number is clickable regardless
• We don't show this icon on MR diffs

Note

• I kept the spacing even between the three gutter items (? icon, blame icon, and line number).
• Space to the left is clickable (same as on prod). Wondering if we should remove this and just have the icons and a small amount of padding outside clickable 🤔

Remove link icon from file gutter

Screenshots or screen recordings

Before	After

How to set up and validate locally

• Go to any file (eg /gitlab-org/gitlab-shell/-/blob/main/spec/gitlab_shell_two_factor_recovery_spec.rb)
• Hover/click on line number (the screenshots also have Explain this code feature enabled)
• Line of code should still be linked to, but the icon shouldn't appear