Test `Microsoft.EntityFrameworkCore.RelationalConnectionTest.HandleTransactionCompleted_with_concurrent_ClearTransactions_is_thread_safe` is flaky

[cincuranet]

Assert.Empty() Failure: Collection was not empty
Collection: [System.ObjectDisposedException: Cannot access a disposed object.
Object name: 'System.Transactions.TransactionScope'.
   at System.Transactions.TransactionScope.Complete()
   at Microsoft.EntityFrameworkCore.RelationalConnectionTest.<>c__DisplayClass46_1.<<HandleTransactionCompleted_with_concurrent_ClearTransactions_is_thread_safe>b__1>d.MoveNext() in /_/test/EFCore.Relational.Tests/RelationalConnectionTest.cs:line 1138]

[MihuBot]

I'm a bot. Here is a possible related and/or duplicate issue (I may be wrong):

• Concurrency error in HandleTransactionCompleted (RelationalConnection) #35856

[cincuranet]

I guess the #36665 was not an entirely correct fix.