Error when serializing request context with circular ref

[ttournie]

Describe the bug
I get a Converting circular structure to JSON when Vendure try to serialize the request-context

To Reproduce

• First you need to install the node package dd-trace (datadog trace)

• Then you create a tracer.ts file in the src folder with :
  import tracer from 'dd-trace'
tracer.init()
export default tracer

• Then in the index.ts and the index-worker.ts add import './tracer' on the top of the file.(You do not need the tracer to actually connect to make the error append)

• Finally to trigger the error you can go to the admin-ui and try to re-index

Expected behavior
It should clean the circular ref