[Docs] PDO MySQL behavior with persistent connections (compared to mysqli)

[AllenJB]

Affected page

https://www.php.net/manual/en/pdo.connections.php#example-1063

Current issue

https://www.php.net/manual/en/mysqli.persistconns.php details several behaviors when using persistent connections with mysqli.

It's not clear/documented if PDO MySQL implements these same behaviors or not.

Suggested improvement

Clearly state in the PDO MySQL documentation whether any cleanup is performed when using persistent connections. If not, this should be clearly stated so developers are aware of the potential issues of persistent connections.

Additional context