Bump Microsoft.CodeAnalysis.CSharp from 4.7.0 to 4.8.0 (#3385)

Bumps [Microsoft.CodeAnalysis.CSharp](https://github.com/dotnet/roslyn) from 4.7.0 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] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

Directory.packages.props

@@ -8,7 +8,7 @@
     <PackageVersion Include="MahApps.Metro" Version="2.4.10" />
     <PackageVersion Include="Microsoft.CodeAnalysis.Analyzers" Version="3.3.4" PrivateAssets="all" />
     <PackageVersion Include="Microsoft.CodeAnalysis.Common" Version="4.8.0" />
-    <PackageVersion Include="Microsoft.CodeAnalysis.CSharp" Version="4.7.0" />
+    <PackageVersion Include="Microsoft.CodeAnalysis.CSharp" Version="4.8.0" />
     <PackageVersion Include="Microsoft.CodeAnalysis.CSharp.Workspaces" Version="4.7.0" />
     <PackageVersion Include="Microsoft.CodeAnalysis.Workspaces.Common" Version="4.7.0" />
     <PackageVersion Include="Microsoft.Composition" Version="1.0.31" />