Revert "Avoid flakiness in test when dropping table"

This reverts commit b061560.

Since we know that CREATE TABLE succeeded the table exists when we drop it.

plugin/trino-redshift/src/test/java/io/trino/plugin/redshift/TestRedshiftTypeMapping.java

@@ -831,7 +831,7 @@ private void runTestCases(String tableName, List<TestCase> testCases)
                             .collect(joining("), (", "VALUES (", ")")));
         }
         finally {
-            getTrinoExecutor().execute("DROP TABLE IF EXISTS " + tableName);
+            getTrinoExecutor().execute("DROP TABLE " + tableName);
         }
     }