update nixpkgs

btcpayserver: 1.11.4 -> 1.11.6
fulcrum: 1.9.1 -> 1.9.2
lnd: 0.16.3-beta -> 0.17.0-beta
nbxplorer: 2.3.65 -> 2.3.66

Includes fix for curl CVE-2023-38545 (https://github.com/NixOS/nixpkgs/pull/260381)

pkgs/default.nix

@@ -34,11 +34,6 @@ let self = {
   secp256k1 = pkgs.callPackage ./secp256k1 { };
   trustedcoin = pkgs.callPackage ./trustedcoin { };
 
-  # TODO-EXTERNAL:
-  # Remove this when https://github.com/lightningnetwork/lnd/pull/7672
-  # has been resolved
-  lnd = pkgsUnstable.callPackage ./lnd { };
-
   pyPkgs = import ./python-packages self pkgs.python3;
   inherit (self.pyPkgs)
     nbPython3Packages