nixos/amazon-image: do not force-load xen-blkfront kernel module

Most AWS instances use Nitro Hypervisor these days which
expose EBS volumes as nvme disks.

And even on previous-generation instances that still use Xen
(like T2) the  xen-blkfront module will be loaded automatically
due to the presence of a modalias.

This fixes #46881

nixos/modules/virtualisation/amazon-image.nix

@@ -49,7 +49,6 @@ in
     boot.extraModulePackages = [
       config.boot.kernelPackages.ena
     ];
-    boot.initrd.kernelModules = [ "xen-blkfront" ];
     boot.initrd.availableKernelModules = [ "nvme" ];
     boot.kernelParams = [ "console=ttyS0,115200n8" "random.trust_cpu=on" ];