Remove the-kenny from list of maintainers in default.nix
Remove the-kenny from list of maintainers in default.nix

Without this fix, the Nix build is broken, which causes `ledger-mode` CI builds to fail.

See https://github.com/NixOS/nixpkgs/commit/887295fd2d8c4da06acdaa185cbb3cc214d83285
ledger/ledger,afh/ledger,afh/ledger,afh/ledger,ledger/ledger,afh/ledger,ledger/ledger,ledger/ledger,afh/ledger,ledger/ledger