flake: update nixpkgs, fix eval

attrpathsSuperset got renamed to preEval in nixpkgs[1] breaking Hydra's
evaluation. Updating nixpkgs to make sure this is consistent now, no
matter if flake-inputs or release.nix is being used.

[1] See commit 19a31658dc39324c9acf8d81198cd7137bdc1e92.

Change-Id: I69ab3f894534b1d89b626ddd4feda8ea502b69b3

flake.lock

@@ -106,11 +106,11 @@
     },
     "nixpkgs_2": {
       "locked": {
-        "lastModified": 1780020239,
-        "narHash": "sha256-ik+V883hTc6GG7TzjxMdhEoMV0hCbQPfsRtNsB1qWUQ=",
+        "lastModified": 1783770249,
+        "narHash": "sha256-K8pGvFito5dp9T0+clr60q+bJPGEskK75aAJ39w7HBM=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "c85dc29a9bcafa665b8ce0654ca019cdb05e63c6",
+        "rev": "62463162b3ce92919f19ada41a70a0d943a08da8",
         "type": "github"
       },
       "original": {

tests/nixpkgs/lib.nix

@@ -61,7 +61,7 @@ symlinkJoin {
           )
         ]
         ++ optionals stdenv.isLinux [
-          ((pkgs.callPackage (nixpkgs + "/ci/eval") { inherit nix; } { }).attrpathsSuperset {
+          ((pkgs.callPackage (nixpkgs + "/ci/eval") { inherit nix; } { }).preEval {
             evalSystem = system;
           })
         ]