Fix test

* testing/lisp/test-org-agenda.el (test-org-agenda/rescale): Remove
  the check against text-scale-mode.  This follows the current
  implementation.

testing/lisp/test-org-agenda.el

@@ -157,7 +157,6 @@
      (text-scale-set 11)
      (cl-assert (and (boundp text-scale-mode) text-scale-mode))
      (org-agenda-redo)
-     (should text-scale-mode)
      (should (= 11 text-scale-mode-amount)))
    (org-test-agenda--kill-all-agendas)))