Update Nix apple sdk usage (#12758)

- the previous usage is a pattern that is being deprecated in nix
- no longer need to add CGO_ENABLED=0 with this method
- bumps flake.lock to get golang 1.21.9 in nix shells

flake.nix

@@ -10,12 +10,9 @@
     flake-utils.lib.eachDefaultSystem (system:
       let
         pkgs = import nixpkgs { inherit system; overlays = [ ]; };
-        # The current default sdk for macOS fails to compile go projects, so we use a newer one for now.
-        # This has no effect on other platforms.
-        callPackage = pkgs.darwin.apple_sdk_11_0.callPackage or pkgs.callPackage;
       in
       rec {
-        devShell = callPackage ./shell.nix {
+        devShell = pkgs.callPackage ./shell.nix {
           inherit pkgs;
         };
         formatter = pkgs.nixpkgs-fmt;

shell.nix

@@ -5,8 +5,13 @@ let
   postgresql = postgresql_14;
   nodejs = nodejs-18_x;
   nodePackages = pkgs.nodePackages.override { inherit nodejs; };
+
+  mkShell' = mkShell.override {
+    # The current nix default sdk for macOS fails to compile go projects, so we use a newer one for now.
+    stdenv = if stdenv.isDarwin then overrideSDK stdenv "11.0" else stdenv;
+  };
 in
-mkShell {
+mkShell' {
   nativeBuildInputs = [
     go
     goreleaser
@@ -46,7 +51,6 @@ mkShell {
   ];
   LD_LIBRARY_PATH = "${stdenv.cc.cc.lib}/lib64:$LD_LIBRARY_PATH";
   GOROOT = "${go}/share/go";
-  CGO_ENABLED = 0;
 
   PGDATA = "db";
   CL_DATABASE_URL = "postgresql://chainlink:chainlink@localhost:5432/chainlink_test?sslmode=disable";