packaging: Drop legacy apple sdk pattern

This has been dropped on unstable an nix no longer
compiled with overridden nixpkgs input. On 25.05 these
overrides already do nothing.

Tested with:

nix build .#packages.x86_64-darwin.nix-cli -L --override-input nixpkgs https://releases.nixos.org/nixos/unstable/nixos-25.11pre859555.ab0f3607a6c7/nixexprs.tar.xz

Default deployment target on 25.05 is 11.3, so 10.13
sdk override doesn't have to be updated at all as evident
from the fact that we didn't observe any issues with it.

packaging/dependencies.nix

@@ -10,27 +10,8 @@
   stdenv,
 }:
 
-let
-  prevStdenv = stdenv;
-in
-
 let
   inherit (pkgs) lib;
-
-  stdenv = if prevStdenv.isDarwin && prevStdenv.isx86_64 then darwinStdenv else prevStdenv;
-
-  # Fix the following error with the default x86_64-darwin SDK:
-  #
-  #     error: aligned allocation function of type 'void *(std::size_t, std::align_val_t)' is only available on macOS 10.13 or newer
-  #
-  # Despite the use of the 10.13 deployment target here, the aligned
-  # allocation function Clang uses with this setting actually works
-  # all the way back to 10.6.
-  # NOTE: this is not just a version constraint, but a request to make Darwin
-  #       provide this version level of support. Removing this minimum version
-  #       request will regress the above error.
-  darwinStdenv = pkgs.overrideSDK prevStdenv { darwinMinVersion = "10.13"; };
-
 in
 scope: {
   inherit stdenv;

src/libstore/package.nix

@@ -64,8 +64,6 @@ mkMesonLibrary (finalAttrs: {
     sqlite
   ]
   ++ lib.optional stdenv.hostPlatform.isLinux libseccomp
-  # There have been issues building these dependencies
-  ++ lib.optional stdenv.hostPlatform.isDarwin darwin.apple_sdk.libs.sandbox
   ++ lib.optional withAWS aws-sdk-cpp;
 
   propagatedBuildInputs = [