Update FSharp.Control.AsyncSeq.Tests.fsproj

Author: beauvankirk

tests/FSharp.Control.AsyncSeq.Tests/FSharp.Control.AsyncSeq.Tests.fsproj

@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>netcoreapp3.1</TargetFrameworks>
+    <TargetFrameworks>net5.0</TargetFrameworks>
     <IsPackable>false</IsPackable>
   </PropertyGroup>
   <ItemGroup>
@@ -12,4 +12,4 @@
     <ProjectReference Include="..\..\src\FSharp.Control.AsyncSeq\FSharp.Control.AsyncSeq.fsproj" />
   </ItemGroup>
   <Import Project="..\..\.paket\Paket.Restore.targets" />
-</Project>
+</Project>