testutils/db: use schema provided by migrate data during export

When exporting, use schema provided by migrate data and not the create data since the migration change the db shema to the migrate version.

internal/testutil/db.go

@@ -672,6 +672,9 @@ func TestMigrate(t *testing.T, lastVersion uint, dataFixtures DataFixtures, setu
 
 				assert.Assert(t, len(diff) == 0, "schema of db created at version %d and db migrated from version %d to version %d is different:\n %s", migrateVersion, createVersion, migrateVersion, diff)
 
+				// set the db schema at the migrated version.
+				dc.Schema = createDataCreate.Tables
+
 				createExport := &bytes.Buffer{}
 				export := &bytes.Buffer{}