fix: define-obsolete-variable-alias require "when" argument in emacs28

[tangxinfa]

The 'when' argument of make-obsolete and related functions is mandatory since https://emba.gnu.org/emacs/emacs/-/commit/32c6732d16385f242b1109517f25e9aefd6caa5c

The use of those functions without a 'when' argument was marked
obsolete back in Emacs-23.1. The affected functions are:
make-obsolete, define-obsolete-function-alias, make-obsolete-variable,
define-obsolete-variable-alias.

See https://github.com/manateelazycat/emacs-application-framework/pull/509

[redguardtoo]

thanks