Use sshSign module on extremophile

machines/extremophile/home.nix

@@ -3,7 +3,12 @@
 {
   nathan = {
     programs = {
-      util = { git = { gpgSign = false; }; };
+      util = {
+        git = {
+          gpgSign = false;
+          sshSign = true;
+        };
+      };
       devel = {
         idris2 = true;
         haskell = false;
@@ -14,12 +19,4 @@
     };
     config = { isDesktop = true; };
   };
-  # Setup git commit signing with ssh key
-  programs.git = {
-    extraConfig = {
-      commit.gpgsign = true;
-      gpg.format = "ssh";
-      user.signingkey = "~/.ssh/id_ed25519.pub";
-    };
-  };
 }