Backport commit 2c639a35a from Emacs

* lisp/org.el: Don't require overlay; that's only needed in XEmacs.

Don't require overlay; that's only needed in XEmacs
2c639a35a6d71d190bea896bbeb14b279e8d8384
Stefan Kangas
Sat Feb 27 18:23:12 2021 +0100

lisp/org.el

@@ -4758,7 +4758,6 @@ This is for getting out of special buffers like capture.")
 (require 'time-date)
 (unless (fboundp 'time-subtract) (defalias 'time-subtract 'subtract-time))
 (require 'easymenu)
-(require 'overlay)
 
 (require 'org-entities)
 (require 'org-faces)