Revert "org: Add font-lock rule for inline export snippets"

This reverts commit 9af8d55f0745b69212889cf5ed5035ea3c293a2a.

lisp/org.el

@@ -5688,11 +5688,6 @@ needs to be inserted at a specific position in the font-lock sequence.")
 	   ;; Description list items
 	   '("^[ \t]*[-+*][ \t]+\\(.*?[ \t]+::\\)\\([ \t]+\\|$\\)"
 	     1 'org-list-dt prepend)
-           ;; Inline export snippets
-           '("\\(@@\\)\\([a-z-]+:\\).*?\\(@@\\)"
-             (1 'font-lock-comment-face t)
-             (2 'org-tag t)
-             (3 'font-lock-comment-face t))
 	   ;; ARCHIVEd headings
 	   (list (concat
 		  org-outline-regexp-bol