fix: Add filterwarnings ignore for jsonschema.RefResolver DeprecationWarning

[matthewfeickert]

Description

Add an ignore to filterwarnings to avoid jsonschema.RefResolver DeprecationWarning

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.

This filterwarning should be removed once pyhf updates to referencing.

• c.f. jsonschema v4.18.0 will introduce breaking changes #2139

Checklist Before Requesting Reviewer

• Tests are passing
• "WIP" removed from the title of the pull request
• Selected an Assignee for the PR to be responsible for the log summary

Before Merging

For the PR Assignees:

• Summarize commit messages into a comprehensive review of the PR

* Add an ignore to filterwarnings to avoid jsonschema.RefResolver DeprecationWarning

> 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.

  This filterwarning should be removed once pyhf updates to referencing.
  - c.f. https://github.com/scikit-hep/pyhf/issues/2139

[matthewfeickert]

@kratsg This currently just pushed Issue #2139 further off, but I hope that we can get that dealt with soon enough that this won't be an actual problem.

[codecov]

Codecov Report

Patch and project coverage have no change.

Comparison is base (a28d1a3) 98.30% compared to head (9ad6479) 98.30%.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2246   +/-   ##
=======================================
  Coverage   98.30%   98.30%           
=======================================
  Files          69       69           
  Lines        4534     4534           
  Branches      802      802           
=======================================
  Hits         4457     4457           
  Misses         45       45           
  Partials       32       32           

Flag	Coverage Δ
contrib	97.88% <ø> (ø)
doctest	61.09% <ø> (ø)
unittests-3.10	96.31% <ø> (ø)
unittests-3.11	96.31% <ø> (ø)
unittests-3.8	96.33% <ø> (ø)
unittests-3.9	96.36% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Do you have feedback about the report comment? Let us know in this issue.

[matthewfeickert]

I'm going to approve and merge this myself. As always, PRs approved by a single core dev can be reverted as needed by the rest of the dev team.