users: add booxter

Requesting access to darwin community-builders for now since I'd like to
reproduce a failure in llama-cpp-python that I can't otherwise reproduce
on my own darwin machine.

modules/darwin/community-builder/keys/booxter

@@ -0,0 +1 @@
+ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIA0W1oVd2GMoSwXHVQMb6v4e3rIMVe9/pr/PcsHg+Uz3 ihrachys@ihrachys-macpro

modules/darwin/community-builder/users.nix

@@ -385,6 +385,13 @@ let
       uid = 560;
       keys = ./keys/katexochen;
     }
+    {
+      # lib.maintainers.booxter, https://github.com/booxter
+      name = "booxter";
+      trusted = true;
+      uid = 561;
+      keys = ./keys/booxter;
+    }
   ];
 in
 {