flake check wants every top level check to be a derivation

.github/workflows/test.yml

@@ -16,4 +16,4 @@ jobs:
         name: selfhostblocks
         authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
     - run: nix flake check
-    - run: nix build .#checks.x86_64-linux.vms.postgresql
+    # - run: nix build .#checks.x86_64-linux.vms.postgresql

flake.nix

@@ -60,9 +60,7 @@
                 ]);
             };
 
-            vms = {
-              postgresql = pkgs.callPackage ./test/vm/postgresql.nix {};
-            };
+            vm_postgresql = pkgs.callPackage ./test/vm/postgresql.nix {};
           };
       }
   );