Bump Microsoft.CodeAnalysis.CSharp from 4.3.1 to 4.8.0

Bumps [Microsoft.CodeAnalysis.CSharp](https://github.com/dotnet/roslyn) from 4.3.1 to 4.8.0.
- [Release notes](https://github.com/dotnet/roslyn/releases)
- [Changelog](https://github.com/dotnet/roslyn/blob/main/docs/Breaking%20API%20Changes.md)
- [Commits](https://github.com/dotnet/roslyn/commits)

---
updated-dependencies:
- dependency-name: Microsoft.CodeAnalysis.CSharp
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

src/Backgrounder.Generators/Backgrounder.Generators.csproj

@@ -17,7 +17,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.3.1" PrivateAssets="all" />
+    <PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.8.0" PrivateAssets="all" />
   </ItemGroup>
 
 </Project>