enable cross compilation for wayland scanner

[planetmarshall]

Summary

Changes to recipe: wayland/1.23.92

Motivation

Enable using wayland-scanner from a cross-compilation environment.

Details

Enables building wayland-scanner from platforms other than Linux and Android so that it can be used as a build requirement in a cross-compilation context. The libraries are disabled as before.

---

• Read the contributing guidelines
• Checked that this PR is not a duplicate: list of PRs by recipe
• Tested locally with at least one configuration using a recent version of Conan

[planetmarshall]

Not sure how to solve this -

wayland/1.23.92 (test package): Calling build()
ERROR: wayland/1.23.92 (test package): Error in build() method, line 45
	wayland_scanner = pkg_config.variables["wayland_scanner"]
	ConanException: PkgConfig failed. Command: pkg-config --print-variables wayland-scanner --print-errors
    stdout:

    stderr:
    /bin/sh: pkg-config: command not found

pkg-config is already specified as a build requirement. I don't see it locally as I have pkg-config from homebrew in the PATH.