community[patch]: standardized sparkllm init args (#21633)

Related to #20085 
@baskaryan 

Thank you for contributing to LangChain!

community:sparkllm[patch]: standardized init args

updated `spark_api_key` so that aliased to `api_key`. Added integration
test for `sparkllm` to test that it continues to set the same underlying
attribute.

updated temperature with Pydantic Field, added to the integration test.

Ran `make format`,`make test`, `make lint`, `make spell_check`

libs/community/tests/integration_tests/chat_models/test_sparkllm.py

@@ -5,11 +5,21 @@ from langchain_community.chat_models.sparkllm import ChatSparkLLM
 
 def test_initialization() -> None:
     """Test chat model initialization."""
+
     for model in [
-        ChatSparkLLM(timeout=30),
-        ChatSparkLLM(request_timeout=30),  # type: ignore[call-arg]
+        ChatSparkLLM(
+            api_key="secret",
+            temperature=0.5,
+            timeout=30,
+        ),
+        ChatSparkLLM(
+            spark_api_key="secret",
+            request_timeout=30,
+        ),  # type: ignore[call-arg]
     ]:
         assert model.request_timeout == 30
+        assert model.spark_api_key == "secret"
+        assert model.temperature == 0.5
 
 
 def test_chat_spark_llm() -> None: