valkey: add nixosTest

nixos/tests/redis.nix

···
   mkTestName =
     pkg: "${pkg.pname}_${builtins.replaceStrings [ "." ] [ "" ] (lib.versions.majorMinor pkg.version)}";
   redisPackages = {
-    inherit (pkgs) redis keydb;
+    inherit (pkgs) redis keydb valkey;
   };
   makeRedisTest =
     {

pkgs/by-name/va/valkey/package.nix

···
   lua,
   jemalloc,
   pkg-config,
+  nixosTests,
   tcl,
   which,
   ps,
···
     runHook postCheck
   '';
 
-  passthru.serverBin = "valkey-server";
+  passthru = {
+    tests.redis = nixosTests.redis;
+    serverBin = "valkey-server";
+  };
 
   meta = with lib; {
     homepage = "https://valkey.io/";