cntr: add passthru.tests

pkgs/applications/virtualization/cntr/default.nix

@@ -1,4 +1,4 @@
-{ lib, rustPlatform, fetchFromGitHub }:
+{ lib, rustPlatform, fetchFromGitHub, nixosTests }:
 
 rustPlatform.buildRustPackage rec {
   pname = "cntr";
@@ -13,6 +13,10 @@ rustPlatform.buildRustPackage rec {
 
   cargoSha256 = "sha256-o8o/ixjYdnezQZEp78brjmR2lvQbiwCJr4Y97tHiYbk=";
 
+  passthru.tests = {
+    nixos = nixosTests.cntr;
+  };
+
   meta = with lib; {
     description = "A container debugging tool based on FUSE";
     homepage = "https://github.com/Mic92/cntr";