remove duplicates in .csproj files

src/ImageSharp/ImageSharp.csproj

@@ -40,7 +40,6 @@
       <PrivateAssets>All</PrivateAssets>
     </PackageReference>
     <PackageReference Include="System.Buffers" Version="4.4.0" />
-    <PackageReference Include="System.Memory" Version="4.4.0-preview1-25305-02" />
     <PackageReference Include="System.Memory" Version="4.4.0-preview2-25405-01" />
     <PackageReference Include="System.Threading.Tasks.Parallel" Version="4.3.0" />
     <PackageReference Include="System.Runtime.CompilerServices.Unsafe" Version="4.4.0" />

tests/ImageSharp.Tests/ImageSharp.Tests.csproj

@@ -16,10 +16,6 @@
     <None Include="PixelFormats\PixelOperationsTests.Blender.cs" />
   </ItemGroup>
   <ItemGroup>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.3.0" />
-    <PackageReference Include="Moq" Version="4.7.1" />
-    <PackageReference Include="xunit" Version="2.3.0-beta3-build3705" />
-    <PackageReference Include="xunit.runner.visualstudio" Version="2.3.0-beta3-build3705" />
     <PackageReference Include="CoreCompat.System.Drawing" Version="1.0.0-beta006" />
     <PackageReference Include="xunit" Version="2.3.0-beta4-build3742" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.3.0-beta4-build3742" />