Average_on_nav_subquery_in_projection is flaky

[AndriySvyryd]

Microsoft.Data.SqlClient.SqlException : The incoming tabular data stream (TDS) protocol stream is incorrect. The MARS TDS header contained errors.
at Microsoft.Data.SqlClient.SqlCommand.<>c.b__164_0(Task1 result) at System.Threading.Tasks.ContinuationResultTaskFromResultTask2.InnerInvoke()
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
--- End of stack trace from previous location where exception was thrown ---
at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot, Thread threadPoolThread)
--- End of stack trace from previous location where exception was thrown ---
at Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteReaderAsync(RelationalCommandParameterObject parameterObject, CancellationToken cancellationToken) in //src/EFCore.Relational/Storage/RelationalCommand.cs:line 543
at Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteReaderAsync(RelationalCommandParameterObject parameterObject, CancellationToken cancellationToken) in //src/EFCore.Relational/Storage/RelationalCommand.cs:line 543
at Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteReaderAsync(RelationalCommandParameterObject parameterObject, CancellationToken cancellationToken) in //src/EFCore.Relational/Storage/RelationalCommand.cs:line 543
at Microsoft.EntityFrameworkCore.Query.RelationalShapedQueryCompilingExpressionVisitor.AsyncQueryingEnumerable1.AsyncEnumerator.MoveNextAsync() in /_/src/EFCore.Relational/Query/RelationalShapedQueryCompilingExpressionVisitor.AsyncQueryingEnumerable.cs:line 99 at Microsoft.EntityFrameworkCore.EntityFrameworkQueryableExtensions.ToListAsync[TSource](IQueryable1 source, CancellationToken cancellationToken) in //src/EFCore/Extensions/EntityFrameworkQueryableExtensions.cs:line 2019
at Microsoft.EntityFrameworkCore.EntityFrameworkQueryableExtensions.ToListAsync[TSource](IQueryable1 source, CancellationToken cancellationToken) in /_/src/EFCore/Extensions/EntityFrameworkQueryableExtensions.cs:line 2019 at Microsoft.EntityFrameworkCore.Query.AsyncSimpleQueryTestBase1.Average_on_nav_subquery_in_projection() in /_/test/EFCore.Specification.Tests/Query/AsyncSimpleQueryTestBase.cs:line 143
--- End of stack trace from previous location where exception was thrown ---

[AndriySvyryd]

Blocked by dotnet/SqlClient#85