editors/emacs: Update to 30.2
- Replace '30.1' in Mk/Uses/emacs.mk with '30.2'.
- Bump PORTREVISION of dependent ports.
ChangLog: https://cgit.git.savannah.gnu.org/cgit/emacs.git/tree/etc/NEWS?h=emacs-30.2
Reviewed by: jrm
Differential Revision: https://reviews.freebsd.org/D51906