Python client is broken due to dependency conflict

[HonahX]

Describe the bug

The current python client in the main is unusable due to a dependency conflict. Specifically, when generating the client using open-api-generator==7.12.0, the client code requires urllib3 >= 2.1.0, < 3.0.0, (ref). However, our client also needs boto3, which is only compatible with urllib3 2.x for Python 3.10+

This leads to 2 ways of solving this

1. Generate the client using open-api-generator==7.11.0 to remove the requirement of urllib 2.x: [BUG][Python] Generator produces unusable clients OpenAPITools/openapi-generator#20826 (comment)
2. Drop support for python 3.9

Since python 3.9's supports ends in October 2025, which means it is still active now, I think we should go with approach 1 to downgrade the generator version used

To Reproduce

For reference, you can reproduce the client error by running spark getting-started example. You will get

File /opt/conda/lib/python3.11/site-packages/urllib3/poolmanager.py:303, in PoolManager.connection_from_host(self, host, port, scheme, pool_kwargs)
    300 request_context["port"] = port
    301 request_context["host"] = host
--> 303 return self.connection_from_context(request_context)

File /opt/conda/lib/python3.11/site-packages/urllib3/poolmanager.py:326, in PoolManager.connection_from_context(self, request_context)
    324 if not pool_key_constructor:
    325     raise URLSchemeUnknown(scheme)
--> 326 pool_key = pool_key_constructor(request_context)
    328 return self.connection_from_pool_key(pool_key, request_context=request_context)

File /opt/conda/lib/python3.11/site-packages/urllib3/poolmanager.py:147, in _default_key_normalizer(key_class, request_context)
    144 if context.get("key_blocksize") is None:
    145     context["key_blocksize"] = _DEFAULT_BLOCKSIZE
--> 147 return key_class(**context)

TypeError: PoolKey.__new__() got an unexpected keyword argument 'key_ca_cert_data'