feat(backport): Use 'method' arg for jax.numpy.percentile (#2524)

* Backport PR #2522.
* 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'.

Co-authored-by: Matthew Feickert <matthew.feickert@cern.ch>

src/pyhf/tensor/jax_backend.py

@@ -328,7 +328,7 @@ def percentile(self, tensor_in, q, axis=None, interpolation="linear"):
 
         .. versionadded:: 0.7.0
         """
-        return jnp.percentile(tensor_in, q, axis=axis, interpolation=interpolation)
+        return jnp.percentile(tensor_in, q, axis=axis, method=interpolation)
 
     def stack(self, sequence, axis=0):
         return jnp.stack(sequence, axis=axis)