Ignore RuntimeWarning "invalid value encountered in cast" for LaxBack…

…edNumpyTests.testUniqueEqualNan

This is to fix Mac arm64 pytests on CI. The tests started failing after integrating ml-dtypes-0.5.0. Ignoring warnings is probably Ok, as it is inspired by a similar PR in ml-dtypes repo itself: jax-ml/ml_dtypes#186

PiperOrigin-RevId: 676277042

tests/lax_numpy_test.py

@@ -2134,6 +2134,9 @@ def np_fun(x):
     self._CheckAgainstNumpy(np_fun, jnp_fun, args_maker)
 
   @jtu.sample_product(dtype=inexact_dtypes, equal_nan=[True, False])
+  @jtu.ignore_warning(
+      category=RuntimeWarning, message='invalid value encountered in cast'
+  )
   def testUniqueEqualNan(self, dtype, equal_nan):
     shape = (20,)
     rng = jtu.rand_some_nan(self.rng())