Release 10.9

Maintenance release for ILIAS 10.
More information about the release at https://docu.ilias.de/go/pg/225479_35. This release contains security fixes. For more information, please visit the security blog at https://docu.ilias.de/go/blog/15821/929. It is recommended to update your software to the latest version.

Please use only the files ILIAS-10.9.tar.gz or ILIAS-10.9.zip for download and installing ILIAS and ignore the files offered by GitHub (called 'Source Code') to prevent problems with composer.