Bumps [phpmailer/phpmailer](https://github.com/PHPMailer/PHPMailer) from 6.3.0 to 6.4.1. **This update includes a security fix.**
- [Release notes](https://github.com/PHPMailer/PHPMailer/releases)
- [Changelog](https://github.com/PHPMailer/PHPMailer/blob/master/changelog.md)
- [Commits](https://github.com/PHPMailer/PHPMailer/compare/v6.3.0...v6.4.1

)

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

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

* Migrate email utils to non-static

* Migrate http utils to non-static

* Migrate net utils to non-static

* Migrate random utils to non-static

* Migrate system utils to non-static

* Migrate time utils to non-static

* Migrate xml utils to non-static

* Upgrade notes

* Update test-framework

* Fix tests

* Start testing on PHP 8.0

* Update test-framework

* Fix broken unit tests

* Fix query; apparently under PHP8 the query would raise PDOException instead of returning false

Convert to our wrapper class for assertions

* Remove deprecated classes

* Remove support for certificate fingerprints

* Remove many deprecated methods and pieces of code

* Remove SAML1.1/Shib1.3 support

* Remove many superfluous annotations

* Update unit test to work with new PHPunit

Closes #1268 
Closes #1020 
Closes #431 
Closes #167 
Closes #151 

Signed-off-by: Jaime Pérez Crespo <jaime.perez@uninett.no>

PSR-12 compliancy