Bug 38237: Add logging to erm_run_harvester cronjob

Bug 38237: Add logging to erm_run_harvester cronjob

This patch simply adds logging to the cronjob

To test:
1 - Enable CronjobLog
    http://localhost:8081/cgi-bin/koha/admin/preferences.pl?op=search&searchfield=CronjobLog
2 - Enable ERMModule
    http://localhost:8081/cgi-bin/koha/admin/preferences.pl?op=search&searchfield=ERMModule
3 - Home -> E-resource Management -> Data providers -> New data provider
    Fill from registry or create your own, but change the URL and put in any required numbers
    We don't need a real test, just to run the ob
4 - perl misc/cronjobs/erm_run_harvester.pl --begin-date 2024-01-01 --dry-run --debug
5 - View the logs, no log of the script
6 - Apply patches
7 - Run the job again
8 - Check logs
9 - Success!

Signed-off-by: Pedro Amorim <pedro.amorim@ptfs-europe.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>