update linkedin provider name to the correct one

[FadyBengoufa]

Description of the issue

Following the documentation of devdojo auth package, I wanted to use linkedin. But it was not working, although google worked, so my setup was correct.

How to reproduce the error

• Follow exactly the docs and try to create a developer app in linkedin (you need a linkedin page for that, create one)
• Activate Share on LinkedIn and Sign In with LinkedIn using OpenID Connect products in the Products section on linkedin developer portal.
• Add auth/linkedin/callback in the Authorized redirect URLs for your app, but it will not work because the linkedin API has changed.

Reason from what I understood: Microsoft has deprecated the old API as of August 1, 2023!

Here some of the references:

• Auth provider for Linkedin not working nextauthjs/next-auth#8831 (comment)

How I fixed it

I read through the linkedin api, and indeed the the API was changed instead of using "linkedin" it's now "linkedin-openid".
You need to change the callback redirect url in linkedin developers portal to auth/linkedin-openid/callback.

Also slack is now "slack-openid" although I haven't tested it, I can try and test it than update it as well.

I'm not sure about something in regards to this issue to be honest, it seems that when I activated the openid in linkedin developers (I can't disable it after), at that point it won't allow me to pass through the linkedin API with the "linkedin" provider but I need to use "linkedin-openid", but maybe If I haven't activated it, it could have worked. This issue needs to be handled so that both would work if that's the case, let me know what do you think.