[CSE-68] Bump nixpkgs revision
[CSE-68] Bump nixpkgs revision

input-output-hk/cardano-sl,input-output-hk/cardano-sl-explorer,input-output-hk/pos-haskell-prototype,input-output-hk/pos-haskell-prototype,input-output-hk/cardano-sl,input-output-hk/pos-haskell-prototype,input-output-hk/cardano-sl,input-output-hk/cardano-sl-explorer,input-output-hk/cardano-sl,input-output-hk/cardano-sl-explorer