Add support for .NET 8 and update version to 2.1.1

Author: TonyTroeff

src/OneBitSoftware.Utilities.OperationResult/OneBitSoftware.Utilities.OperationResult.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>net9.0</TargetFrameworks>
+    <TargetFrameworks>net8.0;net9.0</TargetFrameworks>
     <ImplicitUsings>disable</ImplicitUsings>
     <Nullable>enable</Nullable>
   </PropertyGroup>
@@ -13,8 +13,12 @@
     </None>
   </ItemGroup>
 
-  <ItemGroup>
-    <PackageReference Include="Microsoft.Extensions.Logging.Abstractions" Version="9.0.2" />
+  <ItemGroup Condition="'$(TargetFramework)' == 'net8.0'">
+    <PackageReference Include="Microsoft.Extensions.Logging.Abstractions" Version="8.0.0" />
+  </ItemGroup>
+
+  <ItemGroup Condition="'$(TargetFramework)' == 'net9.0'">
+    <PackageReference Include="Microsoft.Extensions.Logging.Abstractions" Version="9.0.0" />
   </ItemGroup>
 
   <PropertyGroup>
@@ -32,7 +36,7 @@
     <PackageRequireLicenseAcceptance>False</PackageRequireLicenseAcceptance>
     <PackageReadmeFile>README.md</PackageReadmeFile>
     <PackageTags>OneBitSoftware; OperationResult;</PackageTags>
-    <Version>2.1.0</Version>
+    <Version>2.1.1</Version>
   </PropertyGroup>
 
 </Project>