fix: Correct MySQL required SSL mode — it verifies certificates

[claudespice]

Summary

• The mysql_sslmode: required mode uses SslOpts::default() which sets accept_invalid_certs=false and skip_domain_validation=false, meaning it verifies the server certificate against system root CAs and validates the domain name
• The docs incorrectly stated "do not verify the server certificate" and "does not validate the server's identity"
• The Known Limitations section incorrectly stated certificate verification is not supported — the required mode provides equivalent behavior to verify_identity

Changes

• Corrected required mode description to reflect actual certificate verification behavior
• Updated Known Limitations to accurately describe the available SSL modes

Reference

Verified against datafusion-table-providers mysqlpool.rs get_ssl_opts() function — required mode returns SslOpts::default() (verifies certs), while preferred mode explicitly sets with_danger_accept_invalid_certs(true).

Files updated: 1

[github-actions]

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[github-actions]

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