nix: update flake lock

Was unfortunately not able to implement vm test suite before this release. Hopefully the last nixos update we have to follow.

Signed-off-by: Ophestra <cat@gensokyo.uk>

test/sandbox/default.nix

@@ -15,7 +15,9 @@ testers.nixosTest {
       environment.hakurei = lib.mkIf withRace rec {
         # race detector does not support static linking
         package = (pkgs.callPackage ../../package.nix { }).overrideAttrs (previousAttrs: {
-          GOFLAGS = previousAttrs.GOFLAGS ++ [ "-race" ];
+          env = previousAttrs.env // {
+            GOFLAGS = previousAttrs.env.GOFLAGS + " -race";
+          };
         });
         hsuPackage = options.environment.hakurei.hsuPackage.default.override { hakurei = package; };
       };