Trying to isolate a test that's unreliable a bit more

src/CoreTests/using_multiple_document_stores_in_same_host.cs

@@ -372,6 +372,7 @@ public async Task apply_changes_on_startup()
                 {
                     opts.Connection(ConnectionSource.ConnectionString);
                     opts.RegisterDocumentType<User>();
+                    opts.DatabaseSchemaName = "first_store";
                 })
                 .ApplyAllDatabaseChangesOnStartup();
         });