Remove redundant dbus launch, fix sommelier

We're already starting a dbus normally, the wrapped dbus-launch is
not needed. Passing a command also prevents sommelier from working.

Also update sommelier since the old version was broken for virtio-gpu.

packages/sommelier.nix

@@ -18,13 +18,13 @@
 
 stdenv.mkDerivation {
   pname = "sommelier";
-  version = "126.0";
+  version = "git+2216f6a1c1";
 
   src = fetchzip rec {
     url = "https://chromium.googlesource.com/chromiumos/platform2/+archive/${passthru.rev}/vm_tools/sommelier.tar.gz";
-    passthru.rev = "fd3798efe23f2edbc48f86f2fbd82ba5059fd875";
+    passthru.rev = "2216f6a1c1948d6a5fc79b1084e6ac76600e1d2e";
     stripRoot = false;
-    sha256 = "BmWZnMcK7IGaEAkVPulyb3hngsmuI0D1YtQEbqMjV5c=";
+    sha256 = "yhv8gU0byk8dYvNADOtB1pPNmposVFZBncstah1vVgE=";
   };
 
   nativeBuildInputs = [

rootfs-nixos/guest/wayland.nix

@@ -78,7 +78,14 @@ in
       User = "user";
       Group = "user";
 
-      ExecStart = "${sommelier}/bin/sommelier --parent --virtgpu-channel -X --xwayland-path=${pkgs.xwayland}/bin/Xwayland";
+      ExecStart = ''
+        ${sommelier}/bin/sommelier \
+          --log-level=-1 \
+          --parent \
+          --virtgpu-channel \
+          -X \
+          --xwayland-path=${pkgs.xwayland}/bin/Xwayland
+      '';
 
       Restart = "on-failure";
       RestartSec = "5s";