JDBC's tck input component allow non readonly input queries

Wen creating a dataset via a JDBC connection with an input query, it is executed in this method.

Before executing the query, one check is performed via a method named isNotReadOnlySQLQuery(). This method use a regex pattern to ensure that the query starts with a "SELECT" and is readonly

The issue here is that this regex will allow to chain several queries separated with a ';', meaning that you can perform any operation after the first SELECT.
For instance, the following query will be considered as readonly and be executed by the component:

SELECT * FROM my_table; DROP  TABLE  my_table;

However it is obviously NOT readonly, as the table will be dropped. Tested with ypiel on AT.