Merge pull request #227506 from Artturin/nixoverridereq

nix: use [ ] instead null to empty requiredSystemFeatures

pkgs/tools/package-management/nix/default.nix

···
     patches = (args.patches or [ ]) ++ [ ./patches/aws-sdk-cpp-TransferManager-ContentEncoding.patch ];
 
     # only a stripped down version is build which takes a lot less resources to build
-    requiredSystemFeatures = null;
+    requiredSystemFeatures = [ ];
   });
 
   aws-sdk-cpp-nix = (aws-sdk-cpp.override {
···
     customMemoryManagement = false;
   }).overrideAttrs (args: {
     # only a stripped down version is build which takes a lot less resources to build
-    requiredSystemFeatures = null;
+    requiredSystemFeatures = [ ];
   });