Maybe solved:
After downgrading the Arch guest additions package, installing the
downgraded guest additions by the Windows 11 guest and restarting the
Windows 11 guest, it is running for several minutes now without
freezing.
$ uname -r; cat /proc/cmdline; pacman -Q virtualbox{,-ext-oracle,-guest-iso,-host-dkms}
6.0.8-arch1-1
BOOT_IMAGE=../vmlinuz-linux root=LABEL=s3.archlinux ro threadirqs initrd=../intel-ucode.img,../initramfs-linux.img
virtualbox 7.0.2-2
virtualbox-ext-oracle 7.0.2-1
virtualbox-guest-iso 6.1.40-1
virtualbox-host-dkms 7.0.2-2
