Bug: can't unwrap a record on delete using opencdc

[raulb]

Bug description

When trying to delete a record using the opencdc format, unwrap throws an error:

2024-02-02T16:56:03+00:00 ERR pipeline stopped error="node dest-file-output-xkapn00qyn60xog:source-kafka:unwrap-source-kafka stopped with error: error executing processor: failed to write message to DLQ: DLQ nack threshold exceeded (0/1), original error: unwrap: error unwrapping record: unexpected data type string%!(EXTRA <nil>)"

Steps to reproduce

1. Have a pipeline which using a the opencdc processor to unwrap records.
2. Perform a delete operation
3. Notice the error thrown.

Version

v0.9.0-nightly.20240202