formats.javaProperties: Don't set `!allowSubstitutes` in `generate` builder

      in attrsOf elemType;

    generate = name: value:

      pkgs.runCommandLocal name

      pkgs.runCommand name

        {

          # Requirements

          # ============

          #    libraries, but we can't rely on this in

          #    general.

          preferLocalBuild = true;

          passAsFile = [ "value" ];

          value = builtins.toJSON value;

          nativeBuildInputs = [