Migrate MySQL database of redmine to utf8mb4
It currently is not possible to add utf8 characters like 𝕏 or emojis to redmine issues, e.g. to comments as pointed out in https://typo3.slack.com/archives/C041L7V6Q/p1694594824603779
This is due to the database being defined as utf8
instead of utf8mb4
The redmine docs point out to use utf8 only for MySQL < 5.5.2, we are using MariaDB 10.11.
This redmine issue 31921 and this wiki article point out on how to migrate.