dxvk: change targetPlatform to hostPlatform

[ghost]

Description of changes

stdenv.targetPlatform really shouldn't be used by software that doesn't generate or manipulate binaries.

I did a mass replacement in #267229 and this was the only package for which the change affected eval on Linux, so I'm putting it in a
separate PR.

If the previous behavior was correct, we should document why targetPlatform is used here.

Things done

• Built on platform(s)
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• For non-Linux: Is sandboxing enabled in nix.conf? (See Nix manual)
  • sandbox = relaxed
  • sandbox = true
• Tested, as applicable:
  • NixOS test(s) (look inside nixos/tests)
  • and/or package tests
  • or, for functions and "core" functionality, tests in lib/tests or pkgs/test
  • made sure NixOS tests are linked to the relevant packages
• Tested compilation of all packages that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review rev HEAD". Note: all changes have to be committed, also see nixpkgs-review usage
• Tested basic functionality of all binary files (usually in ./result/bin/)
• 23.11 Release Notes (or backporting 23.05 Release notes)
  • (Package updates) Added a release notes entry if the change is major or breaking
  • (Module updates) Added a release notes entry if the change is significant
  • (Module addition) Added a release notes entry if adding a new NixOS module
• Fits CONTRIBUTING.md.

[kjeremy]

It looks like this changes a lot more than dxvk.

[reckenrode]

It looks like the commit from #267291 got pulled into this PR.

The reason for the eval change is the isCross check is broken. DXVK was building using nixpkgs’s support for cross-compilation rather than upstream’s cross file. Instead of fixing the check, I opened #267322 to drop it completely.

[ghost]

It looks like this changes a lot more than dxvk.

It looks like the commit from #267291 got pulled into this PR.

Fixed, thanks.

[ghost]

Closed in favor of

• dxvk: rely on the cross support in nixpkgs #267322