xcode-wrapper: allow xcodebuild to fail in version check

[mroi]

With the current beta of Xcode 16.0, the xcode-wrapper derivation fails with error code 141. No additional output is generated. I traced this back to xcodebuild -version failing when its output is piped to head. I think this is because head closes xcodebuild’s stdout after the first line, which xcodebuild does not like.

Description of changes

Fixed by allowing xcodebuild to fail within the pipe used for version number extraction.

Things done

• Built on platform(s)
  • [ ] x86_64-linux
  • [ ] aarch64-linux
  • [x] x86_64-darwin
  • [ ] aarch64-darwin
• For non-Linux: Is sandboxing enabled in nix.conf? (See Nix manual)
  • [x] 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/)
• 24.11 Release Notes (or backporting 23.11 and 24.05 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.

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