boreal: fix broken keyboard layout on linux 5.12

See keyboardio/Model01-Firmware#109 for details, enabling libinput
seems to solve the problem for now. Fingers crossed.

hosts/boreal/default.nix

@@ -14,6 +14,8 @@ in
       ./home.nix
     ];
 
+  boot.kernelPackages = pkgs.linuxPackages_latest;
+
   # Use the systemd-boot EFI boot loader.
   boot.loader.systemd-boot.enable = true;
   boot.loader.efi.canTouchEfiVariables = true;
@@ -107,6 +109,7 @@ in
       windowManager.i3.enable = true;
       layout = "fr";
       xkbVariant = "us";
+      libinput.enable = true;
     };
   };
   my.displayManager.sddm.enable = true;