[sdk-logs, exporters] investigate if circular refrences are a problem during log record serialization

[pichlermarc]

Description

Complex attributes are allowed in log record attributes and log record bodies. Investigate if the attributes sent to the exporters can contain circular references today. If they can contain circular references, open follow-up issues to address this.

This issue is considered done when

• investigation has been conducted (link examples in comments of this issue for future reference)
• follow-up issues have been created if needed

Additional context

• fix(winston-transport): Add attribute serialization opentelemetry-js-contrib#2352