libsForQt5.qtwayland: Fix cross

[OPNA2608]

Description of changes

#227900 will make qtbase cross work which is technically required to test this, but this change should be easy to comprehend even without it.

qtwayland needs wayland libraries for the hostPlatform:

Checking for Wayland client library... yes
Checking for Wayland cursor library... yes
[...]

And wayland-scanner to execute on the buildPlatform:

Checking for wayland-scanner... yes

So without wayland in buildInputs AND nativeBuildInputs the build gives up under cross, because there is no wayland-scanner for buildPlatform:

Running configuration tests...
Checking for Wayland client library... yes
Checking for Wayland cursor library... yes
Checking for wayland-scanner... no
Checking for Wayland EGL library... yes
Checking for wayland-server... yes
Done running configuration tests.

Configure summary:

Qt Wayland Client ........................ no
Qt Wayland Compositor .................... no

When applied onto #227900, this lets me cross-compile up to bambootracker for aarch64-linux:

Things done

• Built on platform(s)
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• For non-Linux: Is sandbox = true set in nix.conf? (See Nix manual)
• 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.