Updated ASP.NET Core Frameworks

Author: michaelstaib

src/HotChocolate/AspNetCore/Directory.Build.props

@@ -2,7 +2,7 @@
   <Import Project="$([MSBuild]::GetPathOfFileAbove('Directory.Build.props', '$(MSBuildThisFileDirectory)..\'))" />
 
   <PropertyGroup>
-    <TargetFrameworks Condition="'$(IsMacOsArm)' != 'true'">net6.0; net5.0; netcoreapp3.1</TargetFrameworks>
+    <TargetFrameworks Condition="'$(IsMacOsArm)' != 'true'">net6.0</TargetFrameworks>
     <TargetFrameworks Condition="'$(IsMacOsArm)' == 'true'">net6.0</TargetFrameworks>
   </PropertyGroup>