flake.nix: update nixpkgs and remove temporary hosc input

hosc 0.20 is now in nixpkgs-unstable

Author: ahihi

flake.lock

@@ -23,14 +23,6 @@
   inputs = {
     utils.url = "github:numtide/flake-utils";
     nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
-    # Temporarily add `hosc` at the latest v0.20 commit
-    # (nixpkgs currently only has 0.19.1).
-    # See this comment for details:
-    # https://github.com/tidalcycles/Tidal/pull/1022#issuecomment-1610978403
-    hosc = {
-      url = "github:rd--/hosc?rev=e77aa67cd0b99a32498fef246a687ba443c9b4be";
-      flake = false;
-    };
   };
 
   outputs = inputs: let
@@ -46,7 +38,6 @@
 
     mkPackages = pkgs: let
       project = pkgs.haskellPackages.extend (pkgs.haskell.lib.compose.packageSourceOverrides {
-        hosc = inputs.hosc; # Remove once `hosc` is at 0.20 in nixpkgs.
         tidal = ./.;
         tidal-link = ./tidal-link;
         tidal-listener = ./tidal-listener;