[Backend/GLFW] Remove wayland files

[CrackedPixel]

This requires that the user has glfw package installed on their system. I think that is reasonable for linux users using glfw

NOTE: x11 builds (default) are unaffected

cd src
make GLFW_LINUX_ENABLE_WAYLAND=TRUE

cd examples
make GLFW_LINUX_ENABLE_WAYLAND=TRUE

it will compile successfully, and you can detect x11/wayland in code if needed:

    #include <GLFW/glfw3.h>

    // after InitWindow()
    int platform = glfwGetPlatform();
    if (platform == GLFW_PLATFORM_WAYLAND) {
        printf("App using native Wayland backend\n");
    } else if (platform == GLFW_PLATFORM_X11) {
        printf("App using X11/XWayland backend\n");
    } else {
        printf("Unknown platform: %d\n", platform);
    }

[raysan5]

It has been discussed on Discord, we can't assume glfw will be available on target platform, better keepraylib as much self-contained and portable as possible.