Purpose of this pull request

This pull request fixes an issue with JDBC driver selection when dealing with heterogeneous data sources. In the current implementation, DriverManager may select the wrong driver when multiple compatible drivers are available in the classpath. This can cause problems when transferring data between similar databases (like Greenplum to PostgreSQL or MySQL 5 to MySQL 8), where driver "drift" can occur.

The underlying issue exists in the DriverManager's getConnection method implementation: it iterates through all registered drivers and uses the first one that successfully connects to the given URL. As shown in the Java source code, it doesn't prioritize drivers by class name but simply tries each registered driver in sequence:

for(DriverInfo aDriver : registeredDrivers) {
    if(isDriverAllowed(aDriver.driver, callerCL)) {
        try {
            Connection con = aDriver.driver.connect(url, info);
            if (con != null) {
                // Success!
                return (con);
            }
        } catch (SQLException ex) {
            if (reason == null) {
                reason = ex;
            }
        }
    }
}

This behavior means that if multiple drivers can handle the same URL format (e.g., both MySQL 5 and MySQL 8 drivers can handle "jdbc:mysql://..." URLs), the one loaded first will be used, regardless of which one is more appropriate for the specific database version being connected to.

The fix explicitly finds and uses the driver specified by class name before falling back to the default DriverManager behavior, ensuring that the correct driver is used for the connection.

Does this PR introduce any user-facing change?

This PR improves the reliability of JDBC connections when working with heterogeneous data sources, but doesn't change any user-facing API or configuration. Users may notice improved stability when transferring data between similar database systems that require different drivers.

How was this patch tested?

The implementation was tested with various database connections where driver drift could occur, particularly focusing on:

• MySQL 5 to MySQL 8 connections
• PostgreSQL to Greenplum connections
• Multiple JDBC drivers in the classpath

The tests verified that the correct driver is selected when explicitly specified, even when multiple compatible drivers are available.

Check list

• The main modification is an improvement to the org.apache.seatunnel.connectors.seatunnel.jdbc.catalog.AbstractJdbcCatalog#getConnection method, prioritizing the use of the specified driver class to establish connections and avoid driver drift issues
• Related changes include ensuring the driverClass parameter is correctly passed to the getConnection method, allowing the specified driver priority to take effect