Foundations: Remove wiki

[zachmmeyer]

Checks

• This is not a duplicate of an existing issue (please have a look through our open issues list to make sure)
• I have thoroughly read and understand The Odin Project Contributing Guide
• Would you like to work on this issue?

Describe your suggestion

Once #30749 has been completed the Guest Additions wiki page will no longer be needed.

Since it is the last remaining page on the repository wiki the wiki itself should be disabled.

Path

Other / NA

Lesson Url

https://github.com/TheOdinProject/curriculum/wiki/Guest-Additions

(Optional) Discord Name

hateburn

(Optional) Additional Comments

Thanks @mao-sz for this callout!