[Instrumentation.Runtime] Replace .NET 6 target with .NET 8 (open-telemetry#2155)

Co-authored-by: joegoldman2 <[email protected]>
Co-authored-by: Mikel Blanchard <[email protected]>

Author: joegoldman2

src/OpenTelemetry.Instrumentation.Runtime/CHANGELOG.md

@@ -2,6 +2,9 @@
 
 ## Unreleased
 
+* Drop support for .NET 6 as this target is no longer supported and add .NET 8 target.
+  ([#2155](https://github.com/open-telemetry/opentelemetry-dotnet-contrib/pull/2155))
+
 ## 1.9.0
 
 Released 2024-Jun-18

src/OpenTelemetry.Instrumentation.Runtime/OpenTelemetry.Instrumentation.Runtime.csproj

@@ -1,8 +1,9 @@
 <Project Sdk="Microsoft.NET.Sdk">
+
   <PropertyGroup>
     <!-- OmniSharp/VS Code requires TargetFrameworks to be in descending order for IntelliSense and analysis. -->
-    <TargetFrameworks>net6.0;netstandard2.0;net462</TargetFrameworks>
-    <Description>dotnet runtime instrumentation for OpenTelemetry .NET</Description>
+    <TargetFrameworks>net8.0;$(NetStandardMinimumSupportedVersion);$(NetFrameworkMinimumSupportedVersion)</TargetFrameworks>
+    <Description>.NET runtime instrumentation for OpenTelemetry .NET.</Description>
     <PackageTags>$(PackageTags);runtime</PackageTags>
     <MinVerTagPrefix>Instrumentation.Runtime-</MinVerTagPrefix>
     <PackageValidationBaselineVersion>1.9.0</PackageValidationBaselineVersion>
@@ -16,4 +17,5 @@
     <Compile Include="$(RepoRoot)\src\Shared\AssemblyVersionExtensions.cs" Link="Includes\AssemblyVersionExtensions.cs" />
     <Compile Include="$(RepoRoot)\src\Shared\Guard.cs" Link="Includes\Guard.cs" />
   </ItemGroup>
+
 </Project>

test/OpenTelemetry.Instrumentation.Runtime.Tests/OpenTelemetry.Instrumentation.Runtime.Tests.csproj

@@ -2,8 +2,8 @@
 
   <PropertyGroup>
     <!-- OmniSharp/VS Code requires TargetFrameworks to be in descending order for IntelliSense and analysis. -->
-    <TargetFrameworks>$(SupportedNetTargets)</TargetFrameworks>
-    <TargetFrameworks Condition="$(OS) == 'Windows_NT'">$(TargetFrameworks);net462</TargetFrameworks>
+    <TargetFrameworks>$(SupportedNetTargetsWithoutNet6)</TargetFrameworks>
+    <TargetFrameworks Condition="$(OS) == 'Windows_NT'">$(TargetFrameworks);$(NetFrameworkMinimumSupportedVersion)</TargetFrameworks>
   </PropertyGroup>
 
   <ItemGroup>