infisicalsdk: update license

pkgs/by-name/in/infisicalsdk/package.nix

···
   meta = {
     homepage = "https://github.com/Infisical/python-sdk-official";
     description = "Infisical Python SDK";
-    license = lib.licenses.unfree;
+    license = lib.licenses.mit;
     maintainers = with lib.maintainers; [ artur-sannikov ];
   };
 }