feat: Use 'method' arg for jax.numpy.percentile

[matthewfeickert]

Description

• Change the argument name in jax.numpy.percentile from 'interpolation' to 'method'. No change to the lower bounds on jax and jaxlib is required as 'method' already existed as an argument in jax v0.4.1. This just deprecates the use of 'interpolation'.
  • Avoids the following DeprecationWarning in jax v0.4.29+:

DeprecationWarning: The interpolation= argument to 'percentile' is deprecated. Use 'method=' instead.

• c.f. https://github.com/google/jax/pull/21267

The CI is failing given another DeprecationWarning fixed in PR https://github.com/scikit-hep/pyhf/pull/2523.

Checklist Before Requesting Reviewer

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

Before Merging

For the PR Assignees:

• [x] Summarize commit messages into a comprehensive review of the PR

* Change the argument name in jax.numpy.percentile from 'interpolation' to 'method'.
  No change to the lower bounds on jax and jaxlib is required as 'method' already
  existed as an argument in jax v0.4.1. This just deprecates the use of 'interpolation'.
   - Avoids the following DeprecationWarning in jax v0.4.29+:

     > DeprecationWarning: The interpolation= argument to 'percentile' is deprecated.
     > Use 'method=' instead.
   - c.f. https://github.com/google/jax/pull/21267

[matthewfeickert]

@meeseeksdev backport to release/v0.7.x