http://www.berklix.com/~jhs/src/bsd/fixes/FreeBSD/ports/gen/ports-mgmt/pkg/files/patch-update.c.diff
http://bugs.freebsd.org/bugzilla/show_bug.cgi?id=277126

Sun Feb 18 12:29:41 CET 2024
with 12.4-RELEASE pkg upgrade
I got just:
  Updating FreeBSD repository catalogue...
  pkg: http://pkgmir.geo.freebsd.org/FreeBSD:12:amd64/quarterly/meta.txz: Not Found
  repository FreeBSD has no meta file, using default settings
  pkg: http://pkgmir.geo.freebsd.org/FreeBSD:12:amd64/quarterly/packagesite.pkg: Not Found
  pkg: http://pkgmir.geo.freebsd.org/FreeBSD:12:amd64/quarterly/packagesite.txz: Not Found
  Unable to update repository FreeBSD
  Error updating repositories!

Give the user a hint:

*** libpkg/repo/binary/update.c.orig	Wed Aug  3 09:37:06 2022
--- libpkg/repo/binary/update.c	Sun Feb 18 12:10:50 2024
***************
*** 629,634 ****
--- 629,635 ----
  	res = pkg_repo_binary_update_proceed(filepath, repo, &t, force);
  	if (res != EPKG_OK && res != EPKG_UPTODATE) {
  		pkg_emit_notice("Unable to update repository %s", repo->name);
+ 		pkg_emit_notice("Is `uname -r` still supported in http://www.freebsd.org/releases/");
  		goto cleanup;
  	}