ModuleNotFoundError: No module named 'requests' when executing `jax.distributed.initialize()` on TPU Pods
### Description

```python
import jax
jax.distributed.initialize()
```

Error:

```
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/home/ayaka/nfs_share/venv/lib/python3.11/site-packages/jax/_src/distributed.py", line 168, in initialize
    global_state.initialize(coordinator_address, num_processes, process_id, local_device_ids)
  File "/home/ayaka/nfs_share/venv/lib/python3.11/site-packages/jax/_src/distributed.py", line 47, in initialize
    clusters.ClusterEnv.auto_detect_unset_distributed_params(
  File "/home/ayaka/nfs_share/venv/lib/python3.11/site-packages/jax/_src/clusters/cluster.py", line 55, in auto_detect_unset_distributed_params
    coordinator_address = env.get_coordinator_address()
                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/ayaka/nfs_share/venv/lib/python3.11/site-packages/jax/_src/clusters/cloud_tpu_cluster.py", line 54, in get_coordinator_address
    return cls._get_worker_endpoints()[0].split(':')[2] + ':8476'
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/ayaka/nfs_share/venv/lib/python3.11/site-packages/jax/_src/clusters/cloud_tpu_cluster.py", line 74, in _get_worker_endpoints
    return get_metadata('worker-network-endpoints').split(',')
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/ayaka/nfs_share/venv/lib/python3.11/site-packages/jax/_src/clusters/cloud_tpu_cluster.py", line 23, in get_metadata
    import requests  # pytype: disable=import-error
    ^^^^^^^^^^^^^^^
ModuleNotFoundError: No module named 'requests'
```

I think `requests` should be automatically installed when installing JAX.

### What jax/jaxlib version are you using?

jax 0.4.14

### Which accelerator(s) are you using?

TPU

### Additional system info

_No response_

### NVIDIA GPU info

_No response_
diff --git a/setup.py b/setup.py
index de67ff9ef..36294aad6 100644
--- a/setup.py
+++ b/setup.py
@@ -85,8 +85,11 @@ setup(
 
         # Cloud TPU VM jaxlib can be installed via:
         # $ pip install jax[tpu] -f https://storage.googleapis.com/jax-releases/libtpu_releases.html
-        'tpu': [f'jaxlib=={_current_jaxlib_version}',
-                f'libtpu-nightly=={_libtpu_version}'],
+        'tpu': [
+          f'jaxlib=={_current_jaxlib_version}',
+          f'libtpu-nightly=={_libtpu_version}',
+          'requests',  # necessary for jax.distributed.initialize
+        ],
 
         # $ pip install jax[australis]
         'australis': ['protobuf>=3.13,<4'],
['setup.py']