ncps: reference existing NixOS tests

pkgs/by-name/nc/ncps/package.nix

@@ -13,6 +13,7 @@
   python3,
   redis,
   writeShellScriptBin,
+  nixosTests,
   nix-update-script,
 }:
 
@@ -96,6 +97,16 @@ buildGoModule (finalAttrs: {
       subPackages = [ "." ];
     };
 
+    tests = {
+      inherit (nixosTests)
+        ncps
+        ncps-custom-sqlite-directory
+        ncps-custom-storage-local
+        ncps-ha-pg
+        ncps-ha-pg-redis
+        ;
+    };
+
     updateScript = nix-update-script { };
   };