build(deps): bump Microsoft.CodeAnalysis.CSharp.Workspaces (#2210)

Bumps [Microsoft.CodeAnalysis.CSharp.Workspaces](https://github.com/dotnet/roslyn) from 3.2.1 to 3.3.1.
- [Release notes](https://github.com/dotnet/roslyn/releases)
- [Changelog](https://github.com/dotnet/roslyn/blob/master/docs/Breaking%20API%20Changes.md)
- [Commits](https://github.com/dotnet/roslyn/commits)

Signed-off-by: dependabot-preview[bot] <[email protected]>

Author: dependabot-preview[bot]

src/ReactiveUI.Fody.Analyzer.Test/ReactiveUI.Fody.Analyzer.Test.csproj

@@ -4,7 +4,7 @@
     </PropertyGroup>
     <ItemGroup>
         <PackageReference Include="Microsoft.CodeAnalysis.Analyzers" Version="2.9.6" />
-        <PackageReference Include="Microsoft.CodeAnalysis.CSharp.Workspaces" Version="3.2.1" />
+        <PackageReference Include="Microsoft.CodeAnalysis.CSharp.Workspaces" Version="3.3.1" />
         <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.9.0" />
         <PackageReference Include="xunit" Version="2.4.1" />
     </ItemGroup>

src/ReactiveUI.Fody.Analyzer/ReactiveUI.Fody.Analyzer.csproj

@@ -11,7 +11,7 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.CodeAnalysis.Analyzers" Version="2.9.6" PrivateAssets="all" />
-    <PackageReference Include="Microsoft.CodeAnalysis.CSharp.Workspaces" Version="3.2.1" PrivateAssets="all" />
+    <PackageReference Include="Microsoft.CodeAnalysis.CSharp.Workspaces" Version="3.3.1" PrivateAssets="all" />
     <PackageReference Include="System.Collections.Immutable" Version="1.6.0" />
   </ItemGroup>