tweak(builtin): cache the downloaded loaddefs-gen.el file

core/me-builtin.el

@@ -231,13 +231,13 @@ or file path may exist now."
 ;; Due to a bug in Emacs 29.1, you must apply the following change prior
 ;; installation or upgrading TRAMP 2.7.0 from GNU ELPA:
 ;; gnu.org/software/tramp/#ELPA-Installation
-(when (version= emacs-version "29.1")
-  (with-current-buffer
-      (url-retrieve-synchronously
-       "https://git.savannah.gnu.org/cgit/emacs.git/plain/lisp/emacs-lisp/loaddefs-gen.el?h=emacs-29")
-    (goto-char (point-min))
-    (while (looking-at "^.+$") (forward-line))
-    (eval-region (point) (point-max))))
+(when-let ((_ (version= emacs-version "29.1"))
+           (dir (+package-download-from-urls
+                 'emacs-29.1-loaddefs-gen-fix
+                 "https://git.savannah.gnu.org/cgit/emacs.git/plain/lisp/emacs-lisp/loaddefs-gen.el?h=emacs-29")))
+  (with-temp-buffer
+    (insert-file-contents (expand-file-name "loaddefs-gen.el" dir))
+    (eval-region (point-min) (point-max))))
 
 (use-package tramp
   :straight t