Fix deprecated MySQL native passwords

Problem/Motivation

The mysql_native_password authentication plugin is deprecated as of MySQL 8.0.34, disabled by default in MySQL 8.4, and removed as of MySQL 9.0.0.

In MySQL 9.0, caching_sha2_password is the default authentication plugin; mysql_native_password is no longer available. For information about the implications of this change for server operation and compatibility of the server with clients and connectors, see caching_sha2_password as the Preferred Authentication Plugin.

- 8.4 https://dev.mysql.com/doc/refman/8.4/en/native-pluggable-authentication....
- 9.x https://dev.mysql.com/doc/refman/9.0/en/caching-sha2-pluggable-authentic...

At PHP side https://php.watch/articles/fix-php-mysql-84-mysql_native_password-not-lo...

Steps to reproduce

See #3521851: [random test failure] Drupal\FunctionalTests\Bootstrap\UncaughtExceptionTest::testLostDatabaseConnection

Proposed resolution

- 8.4 add config option
- 9.x TBD

Remaining tasks

User interface changes

API changes

Data model changes