nix: update flake lock

NixOS 25.11 introduces a crash in cage and an intermittent crash in foot.

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

test/sandbox/configuration.nix

@@ -6,7 +6,7 @@
 }:
 let
   testProgram = pkgs.callPackage ./tool/package.nix { inherit (config.environment.hakurei.package) version; };
-  testCases = import ./case pkgs.system lib testProgram;
+  testCases = import ./case pkgs.stdenv.hostPlatform.system lib testProgram;
 in
 {
   users.users = {
@@ -33,7 +33,7 @@ in
         hakurei -v run hakurei-test \
           -p "/var/tmp/.hakurei-check-ok.0" \
           -t ${toString (builtins.toFile "hakurei-pd-want.json" (builtins.toJSON testCases.pd.want))} \
-          -s ${testCases.pd.expectedFilter.${pkgs.system}} "$@"
+          -s ${testCases.pd.expectedFilter.${pkgs.stdenv.hostPlatform.system}} "$@"
       '')
     ];