verilator: 4.004 -> 4.006

Semi-automatic update generated by
https://github.com/ryantm/nixpkgs-update tools. This update was made
based on information from
https://repology.org/metapackage/verilator/versions

pkgs/applications/science/electronics/verilator/default.nix

@@ -2,11 +2,11 @@
 
 stdenv.mkDerivation rec {
   name    = "verilator-${version}";
-  version = "4.004";
+  version = "4.006";
 
   src = fetchurl {
     url    = "https://www.veripool.org/ftp/${name}.tgz";
-    sha256 = "1nkdmz4bm1v2xarajf2g3z5vb2611a4fkvpgjxac4xrja5r8wpwk";
+    sha256 = "0vnybpknf4llw3fw800ffiqj89ilbq06j8b2x4syj2gsrlnjvp1i";
   };
 
   enableParallelBuilding = true;