[MySQL] Add support for MariaDB 10.5.X

[Alphayeeeet]

With MariaDB 10.5.X wie get an error on metric query:

[elastic_agent.metricbeat][error] error doing query {events_statements SELECT digest_text, count_star, avg_timer_wait, max_timer_wait, last_seen, quantile_95 FROM performance_schema.events_statements_summary_by_digest ORDER BY avg_timer_wait DESC LIMIT 10 table %!s(bool=true)}%!(EXTRA *mysql.MySQLError=Error 1054: Unknown column 'quantile_95' in 'field list')

[Alphayeeeet]

Please add the performance-metricset to the doc.