Re-enable handling of duplicate hermes ids

[PrenSJ2]

I think because this function is broken, It is called to update on every webhook

Proposed Solution

1. call handle_duplicate_hermes_ids only if the hermes_id is a string
2. only update the objects if there has been a change

[PrenSJ2]

pydantic_core._pydantic_core.ValidationError
1 validation error for PipedriveEvent
previous.8c2f326b6be255cd3d5cf4ee7385eaf544a47f1d
  Input should be a valid integer, unable to parse string as an integer [type=int_parsing, input_value='89718, 89951', input_type=str]
    For further information visit https://errors.pydantic.dev/2.8/v/int_parsing

when rewriting the handling of the duplicate hermes ids

• should not validate / ignore the value in the previous section of the webhook, perhaps by setting it to none, (if the value is a sting with a comma)

[PrenSJ2]