In a previous commmit (1), custom wire width for armatures was disabled
on macOS and a corrisponding warning was added to the UI due to a
limitation at the time leading to rendering artifacts #124691.
These limiations appear to have been sorted in Blender 4.4 and so
custom wire widths now work on macOS. So this commit removes the
warning message form the UI.
(1) a451971026
Pull Request: https://projects.blender.org/blender/blender/pulls/137651