chore(deps): bump github.com/stackitcloud/stackit-sdk-go/services/serverbackup from 1.3.5 to 1.3.8

chore(deps): bump github.com/stackitcloud/stackit-sdk-go/services/serverbackup from 1.3.5 to 1.3.8 #3931