flake: update hydra nixosTests

Author: zowoq

flake.nix

@@ -139,7 +139,7 @@
               nixosTests-buildbot-nix-master = inputs'.buildbot-nix.checks.master;
               nixosTests-buildbot-nix-worker = inputs'.buildbot-nix.checks.worker;
               nixosTests-harmonia = pkgs.nixosTests.harmonia;
-              nixosTests-hydra = pkgs.nixosTests.hydra.hydra;
+              nixosTests-hydra = pkgs.nixosTests.hydra;
             };
         };
     };