prettier: version missmatch between CI and lock file

[FlorianFranzen]

Currently there is a substantial difference between the prettier version installed via yarn and executed via yarn prettier (v2.7) and the version installed and used by the CI (via npm install prettier, currently v3.3).

Due to this difference, the CI actually does no longer pass after running yarn prettier. So either we stop using npm to install prettier on the CI and run it via yarn and the lockfile or we update the version requirements to a similar version to fix the issue till the latest release changes their definition of pretty changes again.