org-element-cache-map: Increase minimal Emacs version in 717a847d6

* lisp/org-element.el (org-element-cache-map): Do not byte-compile
FUNC in Emacs 28 as well.  Some variants of Emacs 28 do not
byte-compile the lambda correctly [1].

[1] https://list.orgmode.org/87tuha62rq.fsf@localhost/T/#ma9f23ef9e96de01c53451f40d097e4ce2fd51571

lisp/org-element.el

@@ -7110,7 +7110,7 @@ of FUNC.  Changes to elements made in FUNC will also alter the cache."
                                ;; somehow alters the FUNC result in
                                ;; Emacs 26 and 27, but not in Emacs
                                ;; >=28.
-                               (version< emacs-version "28"))
+                               (version< emacs-version "29"))
                            func
                          (let ((warning-minimum-log-level :error)
                                (inhibit-message t))