info can loop infinitely leaking memory if passed a recursive list

[braingram]

Description of the problem

Calling info (or search or schema_info) on an AsdfFile containing a recursive list will enter an infinite loop that will leak memory.

Example of the problem

import asdf
af = asdf.AsdfFile()
af['l'] = []
af['l'].append(af['l'])
af.info()  # never returns and consumes an ever increasing amount of memory

System information

asdf version: main
python version: 3.12
operating system: mac osx