RefResolver deprecation

[FulecoRafa]

🐜 Bug Report

The script spec_stats.py has deprecation warnings when using the jsonschema.RefResolver class, which will be removed in the future.

Expected Behavior

• This deprecation warning should not appear when running the script

Current Behavior

• Running the script shows:

DeprecationWarning: jsonschema.RefResolver is deprecated as of v4.18.0, in favor of the https://github.com/python-jsonschema/referencing library, which provides more compliant referencing behavior as well as more flexible APIs for customization. A future release will remove RefResolver. Please file a feature request (on referencing) if you are missing an API for the kind of customization you need.
  ref_resolver: jsonschema.RefResolver

Possible Solution

• Update script logic to not need this class anymore

Steps to Reproduce

1. Run the script passing any openapi.yml file as an argument

Context (Environment)

• This issue prevents pushes to remote that have changes to this script.