Remove net5.0 from benchmarks

Remove net5.0 from the supported benchmark TFMs.

Author: martincostello

tests/HttpClientInterception.Benchmarks/JustEat.HttpClientInterception.Benchmarks.csproj

@@ -5,7 +5,7 @@
     <OutputType>Exe</OutputType>
     <RootNamespace>JustEat.HttpClientInterception</RootNamespace>
     <Summary>Benchmarks for JustEat.HttpClientInterception</Summary>
-    <TargetFrameworks>netcoreapp3.1;net472;net5.0;net6.0</TargetFrameworks>
+    <TargetFrameworks>netcoreapp3.1;net472;net6.0</TargetFrameworks>
   </PropertyGroup>
   <ItemGroup>
     <Content Include="organization.json" CopyToOutputDirectory="PreserveNewest" />