Setup DB replication

[physikerwelt]

Currently, dumps lead to timeouts. Set up db replication to use a slave for backup.

• [x] Set db to readonly mode
• [x] Make backup
• [x] Update MariaDB verion
• [x] Set up second container
• [x] Syncronize data
• [x] Make DB writable again

[physikerwelt]

Backup started 2023.11.03_15.42.19

[physikerwelt]

Replication now works no lag. Still there is thousands of writes to the jobs table.