OK, so I checked like you, and yes it seems I have:
[root@rocky9 ~]# dmesg | grep -i crash
[ 0.000000] Command line: BOOT_IMAGE=(hd0,msdos1)/boot/vmlinuz-5.14.0-362.18.1.el9_3.x86_64 root=UUID=b5e3355a-1ec0-44c0-bec7-fba810bf7b3e ro crashkernel=1G-4G:192M,4G-64G:256M,64G-:512M
[ 0.027658] Reserving 256MB of memory at 1776MB for crashkernel (System RAM: 4095MB)
[ 0.062017] Kernel command line: BOOT_IMAGE=(hd0,msdos1)/boot/vmlinuz-5.14.0-362.18.1.el9_3.x86_64 root=UUID=b5e3355a-1ec0-44c0-bec7-fba810bf7b3e ro crashkernel=1G-4G:192M,4G-64G:256M,64G-:512M
So using some of the posts above with a slight change of setting crashkernel=no:
[root@rocky9 ~]# grubby --update-kernel=ALL --args="crashkernel=no"
[root@rocky9 ~]# grubby --info /boot/vmlinuz-5.14.0-362.18.1.el9_3.0.1.x86_64
index=1
kernel="/boot/vmlinuz-5.14.0-362.18.1.el9_3.0.1.x86_64"
args="ro crashkernel=no"
root="UUID=b5e3355a-1ec0-44c0-bec7-fba810bf7b3e"
initrd="/boot/initramfs-5.14.0-362.18.1.el9_3.0.1.x86_64.img"
title="Rocky Linux (5.14.0-362.18.1.el9_3.0.1.x86_64) 9.3 (Blue Onyx)"
id="269bb085de0744ab8477fd952e23fbc4-5.14.0-362.18.1.el9_3.0.1.x86_64"
we can now see crashkernel=no, and so reboot:
[root@rocky9 ~]# dmesg | grep -i crash
[ 0.000000] Command line: BOOT_IMAGE=(hd0,msdos1)/boot/vmlinuz-5.14.0-362.24.1.el9_3.x86_64 root=UUID=b5e3355a-1ec0-44c0-bec7-fba810bf7b3e ro crashkernel=no
[ 0.026246] crashkernel: memory value expected
[ 0.052301] Kernel command line: BOOT_IMAGE=(hd0,msdos1)/boot/vmlinuz-5.14.0-362.24.1.el9_3.x86_64 root=UUID=b5e3355a-1ec0-44c0-bec7-fba810bf7b3e ro crashkernel=no
no crashkernel or reserved memory.
EDIT: Although now, after doing the command @nazunalika gave:
grubby --remove-args="crashkernel=no" --update=ALL
no output in dmesg for crashkernel whatsoever.