added ssh config for local git pushes

configurations/home-manager/git/default.nix

@@ -0,0 +1,20 @@
+{osConfig, ...}: {
+  home = {
+    username = osConfig.users.users.git.name;
+    homeDirectory = osConfig.users.users.git.home;
+
+    # This value determines the Home Manager release that your configuration is
+    # compatible with. This helps avoid breakage when a new Home Manager release
+    # introduces backwards incompatible changes.
+    #
+    # You should not change this value, even if you update Home Manager. If you do
+    # want to update the value, then make sure to first check the Home Manager
+    # release notes.
+    stateVersion = "23.11"; # Please read the comment before changing.
+  };
+
+  programs.ssh.extraConfig = ''
+    AuthorizedKeysFile
+    /var/lib/forgejo/.ssh/authorized_keys
+  '';
+}