Remove support for upgrading from old bookmark file format
* lisp/bookmark.el (bookmark-alist-from-buffer): Remove support for old bookmark file format. (Bug#37122) (bookmark-upgrade-version-0-alist) (bookmark-upgrade-file-format-from-0) (bookmark-grok-file-format-version) (bookmark-maybe-upgrade-file-format): Declare obsolete. (bookmark-load): Don't call 'bookmark-maybe-upgrade-file-format'. * etc/NEWS: Announce it.