Remove EnsureCreated from CleanDatabase

The EnsureCreated() call was creating tables that were immediately dropped,
which could cause timing issues in CI. The database is already created by
the fixture initialization, so EnsureCreated() is unnecessary.

Author: thromel

test/EFCore.Relational.Specification.Tests/RuntimeMigrationTestBase.cs

@@ -85,7 +85,6 @@ protected virtual List<string> GetTableNames(System.Data.Common.DbConnection con
 
     protected virtual void CleanDatabase(RuntimeMigrationDbContext context)
     {
-        context.Database.EnsureCreated();
         var connection = context.Database.GetDbConnection();
         var wasOpen = connection.State == System.Data.ConnectionState.Open;
         if (!wasOpen)

test/EFCore.SqlServer.FunctionalTests/RuntimeMigrationSqlServerTest.cs

@@ -16,7 +16,6 @@ protected override Assembly ProviderAssembly
 
     protected override void CleanDatabase(RuntimeMigrationDbContext context)
     {
-        context.Database.EnsureCreated();
         var connection = context.Database.GetDbConnection();
         var wasOpen = connection.State == System.Data.ConnectionState.Open;
         if (!wasOpen)