feat: Add support for .NET 8.0 + Update package references

- Updated the .NET version from 6.0.x to 8.0.x in the workflow file.
- Removed the Markdig package reference from the test project.
- Updated the Markdig package reference in the main project from version 0.32.0 to 0.36.2.
- Changed the target frameworks in the main project to net6.0 and net8.0.

These changes ensure compatibility with newer versions of .NET and update dependencies for improved functionality and security.

.github/workflows/build-test.yml

@@ -17,10 +17,10 @@ jobs:
         with:
           fetch-depth: 0 # avoid shallow clone so nbgv can do its work.
 
-      - name: Setup .NET 6.0
+      - name: Setup .NET 8.0
         uses: actions/setup-dotnet@v2
         with:
-          dotnet-version: '6.0.x'
+          dotnet-version: '8.0.x'
 
       - uses: dotnet/[email protected]
         id: nbgv

Nodsoft.Markdig.SyntaxHighlighting.Tests/Nodsoft.Markdig.SyntaxHighlighting.Tests.csproj

@@ -9,7 +9,6 @@
     </PropertyGroup>
 
     <ItemGroup>
-        <PackageReference Include="Markdig" Version="0.32.0" />
         <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.1.0"/>
         <PackageReference Include="NSubstitute" Version="5.0.0" />
         <PackageReference Include="NSubstitute.Analyzers.CSharp" Version="1.0.16">

Nodsoft.Markdig.SyntaxHighlighting/Nodsoft.Markdig.SyntaxHighlighting.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
     <PropertyGroup>
-        <TargetFramework>net6.0</TargetFramework>
+        <TargetFrameworks>net6.0;net8.0</TargetFrameworks>
         <ImplicitUsings>enable</ImplicitUsings>
         <Nullable>enable</Nullable>
         <LangVersion>latest</LangVersion>
@@ -18,13 +18,13 @@
         <RepositoryType>git</RepositoryType>
 
         <PackageReadmeFile>README.md</PackageReadmeFile>
-        <PackageLicenseFile>LICENSE</PackageLicenseFile>
+        <PackageLicenseExpression>ISC</PackageLicenseExpression>
         <PackageIcon>icon.png</PackageIcon>
     </PropertyGroup>
 
     <ItemGroup>
       <PackageReference Include="ColorCode.HTML" Version="2.0.15" />
-      <PackageReference Include="Markdig" Version="0.32.0" />
+      <PackageReference Include="Markdig" Version="0.36.2" />
     </ItemGroup>
 
 </Project>