org-mode: Do not re-bind `bidi-paragraph-direction'

* lisp/org.el (org-mode): Remove the old performance workaround for
right-to-left text in Org buffers.  With newer Emacs settings, it is
the 'left-to-right value of `bidi-paragraph-direction' that causes the
slowdown; not the vice versa.

Old discussion on overriding the defaults:
https://lists.gnu.org/archive/html/emacs-devel/2011-09/msg00285.html
The new discussion with example file demonstrating the performance
problem:
https://orgmode.org/list/87a6iqo7x8.fsf@localhost

lisp/org.el

@@ -4620,7 +4620,6 @@ The following commands are available:
     (org-fold-core-set-folding-spec-property (car org-link--link-folding-spec) :visible t))
   (setq-local outline-regexp org-outline-regexp)
   (setq-local outline-level 'org-outline-level)
-  (setq bidi-paragraph-direction 'left-to-right)
   (when (and (stringp org-ellipsis) (not (equal "" org-ellipsis)))
     (unless org-display-table
       (setq org-display-table (make-display-table)))