itk: 5.4.2 -> 5.4.3 (#396375)

pkgs/development/libraries/itk/5.2.x.nix

···
 import ./generic.nix rec {
   version = "5.2.1";
-  rev = "v${version}";
+  tag = "v${version}";
   sourceSha256 = "sha256-KaVe9FMGm4ZVMpwAT12fA67T0qZS3ZueiI8z85+xSwE=";
 }

pkgs/development/libraries/itk/5.x.nix

···
 import ./generic.nix rec {
-  version = "5.4.2";
-  rev = "refs/tags/v${version}";
-  sourceSha256 = "sha256-aQAqh0Z01JqKm78cmxkpC/+gbdx6wTJQh34c1lN+DR0=";
+  version = "5.4.3";
+  tag = "v${version}";
+  sourceSha256 = "sha256-Ve9AzgzePYb6mJ6OZ6C4YeiggCd4WBxB4Xu3ju5HhAg=";
 }

pkgs/development/libraries/itk/generic.nix

···
 {
   version,
-  rev,
+  tag,
   sourceSha256,
 }:
 
···
   src = fetchFromGitHub {
     owner = "InsightSoftwareConsortium";
     repo = "ITK";
-    inherit rev;
+    inherit tag;
     sha256 = sourceSha256;
   };