Found a solution in another question.

I don't know if there is a better solution but solution I found is to define that route manually in the configuration.

# /config/nelmio_api_doc.yaml
nelmio_api_doc:
    documentation:
        # ... 
        paths:
            /api/revoke:
                get:
                    summary: Revoke JWT Token
                    responses:
                        '200':
                            description: HTTP 200 upon successful token revocation