[core][autoscaler] Remove usage of grpcio from autoscaler SDK

[rickyyx]

Why are these changes needed?

Since we should not be using grpcio python (aligning with this #35472)

Related issue number

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• I've signed off every commit(by using the -s flag, i.e., git commit -s) in this PR.
• I've run scripts/format.sh to lint the changes in this PR.
• I've included any doc changes needed for https://docs.ray.io/en/master/.
  • I've added any new APIs to the API Reference. For example, if I added a
    method in Tune, I've added it in doc/source/tune/api/ under the
    corresponding .rst file.
• I've made sure the tests are passing. Note that there might be a few flaky tests, see the recent failures at https://flakey-tests.ray.io/
• Testing Strategy
  • Unit tests
  • Release tests
  • This PR is not tested :(

[rickyyx]

The test is at

ray/python/ray/autoscaler/v2/tests/test_sdk.py

Lines 49 to 71 in 374eb2c

	def test_request_cluster_resources_basic(shutdown_only):
	ray.init(num_cpus=1)
	stub = _autoscaler_state_service_stub()
	# Request one
	request_cluster_resources([{"CPU": 1}])
	def verify():
	reply = get_cluster_resource_state(stub)
	assert_cluster_resource_constraints(reply, [{"CPU": 1}])
	return True
	wait_for_condition(verify)
	# Request another overrides the previous request
	request_cluster_resources([{"CPU": 2, "GPU": 1}, {"CPU": 1}])
	def verify():
	reply = get_cluster_resource_state(stub)
	assert_cluster_resource_constraints(reply, [{"CPU": 2, "GPU": 1}, {"CPU": 1}])
	return True
	wait_for_condition(verify)