wscript: use pkg-config for vulkan check

wscript

@@ -805,7 +805,7 @@ video_output_features = [
     }, {
         'name': '--vulkan',
         'desc':  'Vulkan context support',
-        'func': check_cc(header_name='vulkan/vulkan.h', lib='vulkan'),
+        'func': check_pkg_config('vulkan'),
     }, {
         'name': '--shaderc',
         'desc': 'libshaderc SPIR-V compiler',