efcore: Test runner failing on release/5.0 because of new VB analyzer dependency

Main branch is working fine.

Error:

CSC : error AD0001: Analyzer 'Microsoft.EntityFrameworkCore.InternalUsageDiagnosticAnalyzer' threw an exception of type
'System.IO.FileNotFoundException' with message 
'Could not load file or assembly 'Microsoft.CodeAnalysis.VisualBasic, Version=3.7.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'. The system cannot find the file specified.
[/home/ajcvickers/efcore/src/EFCore.Proxies/EFCore.Proxies.csproj]

for all the tests.