Update to latest Veldrid

Author: kant2002

src/ImGui.NET.SampleProgram/ImGui.NET.SampleProgram.csproj

@@ -9,14 +9,10 @@
 
   <ItemGroup>
     <ProjectReference Include="..\ImGui.NET\ImGui.NET.csproj" />
-    <PackageReference Include="Veldrid" Version="4.8.0" />
-    <PackageReference Include="Veldrid.StartupUtilities" Version="4.8.0" />
+    <PackageReference Include="Veldrid" Version="4.9.0" />
+    <PackageReference Include="Veldrid.StartupUtilities" Version="4.9.0" />
     <ProjectReference Include="..\ImPlot.NET\ImPlot.NET.csproj" />
   </ItemGroup>
-  
-  <ItemGroup>
-    <RdXmlFile Include="rd.xml" />
-  </ItemGroup>
 
   <ItemGroup>
     <EmbeddedResource Include="Shaders/GLSL/imgui-vertex.glsl" LogicalName="imgui-vertex.glsl" />