Bump premailer from `9b4e1ec` to `6d78d1c`
Bump premailer from `9b4e1ec` to `6d78d1c`

Bumps [premailer](https://github.com/ragesoss/premailer) from `9b4e1ec` to `6d78d1c`.
- [Release notes](https://github.com/ragesoss/premailer/releases)
- [Commits](https://github.com/ragesoss/premailer/compare/9b4e1ec78a84605816dc90b0cd4e943650646658...6d78d1cdeb5bfb802106ea1a2886d7b41a70513e)

Signed-off-by: dependabot-preview[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
WikiEducationFoundation/WikiEduDashboard,WikiEducationFoundation/WikiEduDashboard,WikiEducationFoundation/WikiEduDashboard,WikiEducationFoundation/WikiEduDashboard,WikiEducationFoundation/WikiEduDashboard