[JAX] Replace uses of jnp.array in types with jnp.ndarray. (#26703)

`jnp.array` is a function, not a type:
https://jax.readthedocs.io/en/latest/_autosummary/jax.numpy.array.html
so it never makes sense to use `jnp.array` in a type annotation. Presumably the intent was to write `jnp.ndarray` aka `jax.Array`.

Co-authored-by: Peter Hawkins <phawkins@google.com>

examples/flax/speech-recognition/run_flax_speech_recognition_seq2seq.py

@@ -360,7 +360,7 @@ def write_metric(summary_writer, train_metrics, eval_metrics, train_time, step):
 
 def create_learning_rate_fn(
     num_train_steps: int, num_warmup_steps: int, learning_rate: float
-) -> Callable[[int], jnp.array]:
+) -> Callable[[int], jnp.ndarray]:
     """Returns a linear warmup, linear_decay learning rate function."""
     warmup_fn = optax.linear_schedule(init_value=0.0, end_value=learning_rate, transition_steps=num_warmup_steps)
     decay_fn = optax.linear_schedule(