Azure Functions FileNotFoundException workaround

When running in Azure Functions you may stuck into exception

System.IO.FileNotFoundException
HResult=0x80070002
Message=Could not load file or assembly 'Microsoft.CodeAnalysis, Version=3.6.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'. The system cannot find the file specified.
Source=RazorEngineCore
StackTrace:
at RazorEngineCore.RazorEngineCompilationOptions..ctor()
at RazorEngineCore.RazorEngineCompilationOptionsBuilder..ctor(RazorEngineCompilationOptions options)

It is due to known Azure Functions build bug: https://github.com/Azure/azure-functions-host/issues/5894

To work around the issue, add the following to your csproj file to prevent the cleanup:

  <PropertyGroup>
    <_FunctionsSkipCleanOutput>true</_FunctionsSkipCleanOutput>
  </PropertyGroup>

Thanks to @AndyMDoyle