sudo-rs: add meta.mainProgram (#401168)

nixos/modules/security/sudo-rs.nix

@@ -286,7 +286,7 @@ in
       in
       {
         sudo = {
-          source = "${cfg.package.out}/bin/sudo";
+          source = "${lib.getExe cfg.package}";
           inherit
             owner
             group

pkgs/by-name/su/sudo-rs/package.nix

@@ -84,6 +84,7 @@ rustPlatform.buildRustPackage rec {
       mit
     ];
     maintainers = with maintainers; [ nicoo ];
+    mainProgram = "sudo";
     platforms = platforms.linux;
   };
 }