All APIs - Concurrent modification issue while removing blank headers

In Postman 10.7.1 for MacOS, `pm.request.headers.each()` in the pre-request script fails when removing headers while iterating over them:
> TypeError: Cannot read properties of undefined (reading 'value')

See details provided in #61.

Start with the pre-request script usage of pm.request.headers.each() described here and compare it with the details in issue #61. Reproduce the failure in Postman 10.7.1 on macOS while removing blank headers during iteration; done means the iteration no longer raises the reported TypeError.

Written by the indexing model from the issue text.