Avoid spurious byte-compiler warnings in package-quickstart.el

* lisp/emacs-lisp/package.el (package-quickstart-refresh): Disable the
"`make-variable-buffer-local' not called at toplevel" byte-compiler
warnings.  Given that we wrap it all in a let-form, these are mostly
false positives and not helpful.

lisp/emacs-lisp/package.el

@@ -4195,6 +4195,7 @@ activations need to be changed, such as when `package-load-list' is modified."
 ;; Local\sVariables:
 ;; version-control: never
 ;; no-update-autoloads: t
+;; byte-compile-warnings: (not make-local)
 ;; End:
 "))
     ;; FIXME: Do it asynchronously in an Emacs subprocess, and