BC-8772 - Update eslint to v9 and prettier to v3

[bergatco]

Description

Update eslint and prettier as well as all "connected" packages to the latest versions.

Links to Tickets or other pull requests

JRIA :

• https://ticketsystem.dbildungscloud.de/browse/BC-8772

Deployments :

• https://bc-8772.dbc.dbildungscloud.dev/
• https://bc-8772.brb.dbildungscloud.dev/
• https://bc-8772.nbc.dbildungscloud.dev/
• https://bc-8772.thr.dbildungscloud.dev/

Approval for review

• [ ] DEV: If api was changed - generate-client:server was executed in vue frontend and changes were tested and put in a PR with the same branch name.
• [ ] QA: In addition to review, the code has been manually tested (if manual testing is possible)
• [ ] All points were discussed with the ticket creator, support-team or product owner. The code upholds all quality guidelines from the PR-template.