They have! It's these developers either not knowing or not caring about it which is the issue! I did a blog post about this a while back showing how they do it, and how you can get around it, it's not very complex for the devs.

https://www.linkedin.com/pulse/how-linkedin-knows-which-chro...

There's nothing to patch, scanning is not possible.

It's either the extension's choice to become detectable ("externally_connectable" is off by default) or it makes unique changes to websites that allow for its detection.