Backport commit 0a4aa2894 from Emacs

* lisp/org.el: Don't require 'font-lock'; it is preloaded since
version 22.1.

Remove redundant requires of 'font-lock'
0a4aa2894297c0fd9e735328bbb60b427e0ba5d4
Stefan Kangas
Thu Dec 3 08:50:14 2020 +0100

lisp/org.el

@@ -4973,8 +4973,6 @@ the rounding returns a past time."
 
 ;;;; Font-Lock stuff, including the activators
 
-(require 'font-lock)
-
 (defconst org-match-sexp-depth 3
   "Number of stacked braces for sub/superscript matching.")