test: update target frameworks

Author: phnx47

tests/Prometheus.Client.AspNetCore.Tests.csproj

@@ -1,20 +1,16 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>netcoreapp3.1;net6.0;net7.0</TargetFrameworks>
+    <TargetFrameworks>net6.0;net8.0</TargetFrameworks>
     <IsPackable>false</IsPackable>
-    <InvariantGlobalization>true</InvariantGlobalization>
     <NoWarn>$(NoWarn);CS0618</NoWarn>
   </PropertyGroup>
-  <ItemGroup Condition="'$(TargetFramework)' == 'netcoreapp3.1'">
-    <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="3.1.32" />
-  </ItemGroup>
-  <ItemGroup Condition="'$(TargetFramework)' == 'net6.0'">
-    <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="6.0.1" />
-  </ItemGroup>
-  <ItemGroup Condition="'$(TargetFramework)' == 'net7.0'">
-    <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="7.0.0" />
-  </ItemGroup>
   <ItemGroup>
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.10.0" />
+    <PackageReference Include="xunit" Version="2.9.0" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="2.8.2">
+      <PrivateAssets>all</PrivateAssets>
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets>
+    </PackageReference>
     <PackageReference Include="coverlet.collector" Version="6.0.2">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
@@ -23,14 +19,7 @@
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
     </PackageReference>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.10.0" />
-    <PackageReference Include="xunit" Version="2.9.0" />
-  </ItemGroup>
-  <ItemGroup Condition="'$(TargetFramework)' != 'netcoreapp3.1'" >
-    <PackageReference Include="xunit.runner.visualstudio" Version="2.8.2" />
-  </ItemGroup>
-  <ItemGroup Condition="'$(TargetFramework)' == 'netcoreapp3.1'">
-    <PackageReference Include="xunit.runner.visualstudio" Version="2.4.*" />
+    <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="8.0.0" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\src\Prometheus.Client.AspNetCore.csproj" />