Disable magit-gh-pulls

After my hard drive fried, I lost important configuration settings.
Since then, I haven't been able to use `magit-gh-pulls` without it
incessantly prompting me for my GH username and password. Until I
remember how I previously configured this, I'm disabling it.

emacs.d/wpc/packages/wpc-git.el

@@ -10,8 +10,5 @@
 
 (use-package magit)
 
-(use-package magit-gh-pulls
-  :ghook ('magit-mode-hook #'turn-on-magit-gh-pulls))
-
 (provide 'wpc-git)
 ;;; git.el ends here