Bump phpmailer/phpmailer from 6.2.0 to 6.3.0

Bumps [phpmailer/phpmailer](https://github.com/PHPMailer/PHPMailer) from 6.2.0 to 6.3.0.
- [Release notes](https://github.com/PHPMailer/PHPMailer/releases)
- [Changelog](https://github.com/PHPMailer/PHPMailer/blob/master/changelog.md)
- [Commits](PHPMailer/PHPMailer@v6.2.0...v6.3.0)

Fixes #27118, PR #1741

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>