[CI] Forgejo tests

checks/default.nix

@@ -1,7 +1,10 @@
 {
-  perSystem = {config, ...}: {
+  perSystem = {config, pkgs, ...}: {
     checks = {
       inherit (config.packages) ccrEmacs;
+      test = pkgs.hello.overrideDerivation (_: {
+	name = "test";
+      });
     };
   };
 }