redict.tests: fix the eval

Without the change the test fails to eval as it does not exits:

    $ nix build --no-link -f. redict.tests.redict
    error: attribute 'redict' missing
           at pkgs/by-name/re/redict/package.nix:83:27:
               82|
               83|   passthru.tests.redict = nixosTests.redict;
                 |                           ^
               84|
           Did you mean redis?

pkgs/by-name/re/redict/package.nix

@@ -6,7 +6,6 @@
   lua,
   jemalloc,
   pkg-config,
-  nixosTests,
   tcl,
   which,
   ps,
@@ -104,8 +103,6 @@ stdenv.mkDerivation (finalAttrs: {
     runHook postCheck
   '';
 
-  passthru.tests.redict = nixosTests.redict;
-
   meta = {
     homepage = "https://redict.io";
     description = "Distributed key/value store";