[Menu] Fix dispose error

Author: vnbaaij

src/Core/Components/Menu/FluentMenu.razor.cs

@@ -240,14 +240,14 @@ protected override async Task OnAfterRenderAsync(bool firstRender)
                 }
             }
 
-            if (_jsModule is not null)
+            if (_jsModule is not null && _anchoredRegionModule is not null)
             {
                 await _jsModule.InvokeVoidAsync("initialize", Anchor, Id, Open, _anchoredRegionModule, _dotNetHelper);
             }
         }
         else
         {
-            if (_jsModule is not null && _reinitializeEventListeners)
+            if (_jsModule is not null && _anchoredRegionModule is not null && _reinitializeEventListeners)
             {
                 // If the menu was closed, remove its set event listeners. If it opened (ie if the menu starts out closed),
                 // we should set them now.
@@ -397,13 +397,13 @@ public async ValueTask DisposeAsync()
 
         try
         {
-            if(_jsModule is not null)
+            if (_jsModule is not null)
             {
                 await _jsModule.InvokeVoidAsync("dispose", Anchor);
                 await _jsModule.DisposeAsync();
             }
 
-            if(_anchoredRegionModule is not null)
+            if (_anchoredRegionModule is not null)
             {
                 await _anchoredRegionModule.DisposeAsync();
             }