Remove unused render_lock_icon method
What does this MR do?
This method has been introduced in e4f9e2d3 and its usages were removed. Let's remove the method itself
The 17.0 major release is coming on May 16, 2024! This version brings many exciting improvements to GitLab, but also removes some deprecated features. We are introducing three breaking change windows during which we expect breaking changes to be deployed to GitLab.com. You can read more about it on our blogpost. The third breaking change window begins 2024-05-06 09:00 UTC and ends 2024-05-08 22:00 UTC.
This method has been introduced in e4f9e2d3 and its usages were removed. Let's remove the method itself