Merge pull request #254361 from zzzsyyy/update/xanmod

let

  # These names are how they are designated in https://xanmod.org.

  ltsVariant = {

    version = "6.1.47";

    hash = "sha256-yF05EkQ/sAvmoNW2waxNJRGGB0gnL85fFdl6pc6U8Eo=";

    version = "6.1.52";

    hash = "sha256-uzBmgrjNto2CwqkxdFCPeEPQnPSUZEO2pYMnKe8rCfY=";

    variant = "lts";

  };

  mainVariant = {

    version = "6.4.12";

    hash = "sha256-rvSQJb9MIOXkGEjHOPt3x+dqp1AysvQg7n5yYsg95fk=";

    version = "6.4.15";

    hash = "sha256-WupJJMLqgHJ7FATwNyMwAHIUl9qj0lNH7wRYRBm0CAA=";

    variant = "main";

  };