python3Packages.eth-hash: fix build with structuredAttrs (#471526)

pkgs/development/python-modules/eth-hash/default.nix

@@ -32,7 +32,7 @@ buildPythonPackage rec {
   ]
   ++ optional-dependencies.pycryptodome
   # safe-pysha3 is not available on pypy
-  ++ lib.optional (!isPyPy) optional-dependencies.pysha3;
+  ++ lib.optionals (!isPyPy) optional-dependencies.pysha3;
 
   # Backends need to be tested separately and can not use hook
   checkPhase = ''
@@ -51,6 +51,8 @@ buildPythonPackage rec {
     pysha3 = [ safe-pysha3 ];
   };
 
+  __structuredAttrs = true;
+
   meta = {
     description = "Ethereum hashing function keccak256";
     homepage = "https://github.com/ethereum/eth-hash";