On the Internet I've only found this:
/etc/kernel/postinst.d/51-dracut-rescue-postinst.sh $(uname -r) /boot/vmlinuz-$(uname -r)
but it doesn't work in Fedora 36 and soon to be released version 37, because this file is missing, in fact the entire /etc/kernel/postinst.d/ directory is empty.
I've also found
dnf reinstall kernel-core
but it only works for an up-to-date kernel. I'm running the kernel which is no longer available in repositories. Also, this is not a good option per se since it will result in reinstalling literally many hundreds of files for no reason.
grep -r rescue /etc finds nothing.
# grep -r rescue /usr/bin
grep: /usr/bin/tdbdump: binary file matches
grep: /usr/bin/ctags: binary file matches
grep: /usr/bin/systemctl: binary file matches
grep: /usr/bin/systemd-analyze: binary file matches
grep: /usr/bin/efisecdb: binary file matches
grep: /usr/bin/dpkg: binary file matches
grep: /usr/bin/grub2-mkrescue: binary file matches
/usr/share contains a ton of matches but I've no idea how to work with that.
kernel-core and kernel-modules packages have RPM scripts that do something but there's nothing specific to "rescue". It looks like it's all done as a single operation but I don't want to regenerate the initrd.