[Exporter.Instana] Replace .NET 6 target with .NET 8 for test project (open-telemetry#2183)

Co-authored-by: joegoldman2 <[email protected]>
Co-authored-by: Piotr Kiełkowicz <[email protected]>

Author: joegoldman2

src/OpenTelemetry.Exporter.Instana/OpenTelemetry.Exporter.Instana.csproj

@@ -2,17 +2,17 @@
 
   <PropertyGroup>
     <!-- OmniSharp/VS Code requires TargetFrameworks to be in descending order for IntelliSense and analysis. -->
-    <TargetFrameworks>netstandard2.0;$(NetFrameworkMinimumSupportedVersion)</TargetFrameworks>
+    <TargetFrameworks>$(NetStandardMinimumSupportedVersion);$(NetFrameworkMinimumSupportedVersion)</TargetFrameworks>
     <PackageTags>Instana Tracing APM</PackageTags>
-    <Description>Instana .NET Exporter for OpenTelemetry</Description>
+    <Description>Instana .NET Exporter for OpenTelemetry.</Description>
     <MinVerTagPrefix>Exporter.Instana-</MinVerTagPrefix>
     <PackageValidationBaselineVersion>1.0.3</PackageValidationBaselineVersion>
   </PropertyGroup>
 
   <ItemGroup>
     <PackageReference Include="OpenTelemetry" Version="$(OpenTelemetryCoreLatestVersion)" />
 
-    <!--We need the package reference to `System.Net.Http` to use `HttpClientHandler.ServerCertificateCustomValidationCallback` property
+    <!-- We need the package reference to `System.Net.Http` to use `HttpClientHandler.ServerCertificateCustomValidationCallback` property
     on net462 target. Starting net471, we could just add an assembly `Reference` instead of `PackageReference`.
 
     For example:

test/OpenTelemetry.Exporter.Instana.Tests/OpenTelemetry.Exporter.Instana.Tests.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>$(SupportedNetTargets)</TargetFrameworks>
+    <TargetFrameworks>$(SupportedNetTargetsWithoutNet6)</TargetFrameworks>
     <TargetFrameworks Condition="$(OS) == 'Windows_NT'">$(TargetFrameworks);$(NetFrameworkMinimumSupportedVersion)</TargetFrameworks>
   </PropertyGroup>