Fix #135294: Improve missing VR support error message on macOS

This commit improves the error message explaining why VR isn't
supported on the macOS platform.

Pull Request: https://projects.blender.org/blender/blender/pulls/135302

scripts/addons_core/viewport_vr_preview/gui.py

@@ -241,8 +241,12 @@ class VIEW3D_PT_vr_info(bpy.types.Panel):
         return not bpy.app.build_options.xr_openxr
 
     def draw(self, context):
+        import platform
         layout = self.layout
-        layout.label(icon='ERROR', text="Built without VR/OpenXR features")
+        missing_support_string = "Built without VR/OpenXR features"
+        if platform.system() == "Darwin":
+            missing_support_string = "VR is not supported on macOS at the moment"
+        layout.label(icon='ERROR', text=missing_support_string)
 
 
 classes = (