community auto-submit: remove notification about request acceptance for system user

[anikachurilova]

If the community's review_policy is set to open or members, then users are able to submit a record to a community, bypassing the review process. In this case, the review request is still created and auto-accepted by System.

The problem: System user receives a notification that request was accepted. Probably an if is needed somewhere here: https://github.com/inveniosoftware/invenio-rdm-records/blob/9519c1bd765b47b618e7820dd4fd47bfc9571c4d/invenio_rdm_records/requests/community_submission.py#L84

Sentry exception: https://cds-sentry.web.cern.ch/sentry/cds-rdm/issues/34056/events/816855/