editors/emacs: Update to 24.4, an emergency bugfix release

Emacs 29.4 is an emergency bugfix release; it includes no new features
except a small number of changes intended to resolve a security
vulnerability uncovered in Emacs 29.3 and earlier.

https://lists.gnu.org/archive/html/info-gnu-emacs/2024-06/msg00000.html

Reviewed by: ashish, yasu
Sponsored by: The FreeBSD Foundation
Security: https://vuxml.freebsd.org/freebsd/4f6c4c07-3179-11ef-9da5-1c697a616631.html
Differential Revision: https://reviews.freebsd.org/D45703