Fix wrong-type-argument: sequencep from org-agenda

Caused by +org|exclude-agenda-buffers-from-workspace assuming
org-agenda-new-buffers would always be non-nil... then it wasn't.

Reported by @ar1a

modules/lang/org/config.el

@@ -352,8 +352,11 @@ between the two."
                       (IS-LINUX "xdg-open \"%s\"")))))
   ;; Don't clobber recentf or current workspace with agenda files
   (defun +org|exclude-agenda-buffers-from-workspace ()
+    (when org-agenda-new-buffers
       (let (persp-autokill-buffer-on-remove)
-      (persp-remove-buffer org-agenda-new-buffers (get-current-persp) nil)))
+        (persp-remove-buffer org-agenda-new-buffers
+                             (get-current-persp)
+                             nil))))
   (add-hook 'org-agenda-finalize-hook #'+org|exclude-agenda-buffers-from-workspace)
 
   (defun +org*exclude-agenda-buffers-from-recentf (orig-fn &rest args)