nixos/virtualisation.hypervGuest: use elevator=noop

Microsoft recommends the NOOP I/O scheduler for disk performance in HYPER-V:

https://docs.microsoft.com/en-us/windows-server/virtualization/hyper-v/best-practices-for-running-linux-on-hyper-v

> NOOP is a first-in first-out queue that passes the schedule decision
> to be made by the hypervisor. It is recommended to use NOOP as the
> scheduler when running Linux virtual machine on Hyper-V.

nixos/modules/virtualisation/hyperv-guest.nix

@@ -32,7 +32,7 @@ in {
       ];
 
       kernelParams = [
-        "video=hyperv_fb:${cfg.videoMode}"
+        "video=hyperv_fb:${cfg.videoMode} elevator=noop"
       ];
     };