Migrate from Jobrunners to EventGate (required for qlever)

[physikerwelt]

• Install https://www.mediawiki.org/wiki/Extension:EventBus (easy)
• Set up backend (own subtask in other repo?)

Cleanup tasks

• remove redis
• remove jobrunner
• remove rescheduler

[eloiferrer]

Duplicate MaRDI4NFDI/MaRDIRoadmap#129
Done.