(improvement)(project) Remove Python module and related Python code. (#1263)

launchers/standalone/src/main/resources/langchain4j-config.yaml

@@ -4,11 +4,11 @@ langchain4j:
       # Replace with your LLM configs
       # Note: The default API key `demo` is provided by langchain4j community
       #       which limits 1000 tokens per request.
-      base-url: ${OPENAI_API_BASE:https://api.openai.com/v1}
-      api-key: ${OPENAI_API_KEY:demo}
-      model-name: ${OPENAI_MODEL_NAME:gpt-3.5-turbo}
-      temperature: ${OPENAI_TEMPERATURE:0.0}
-      timeout: ${OPENAI_TIMEOUT:PT60S}
+      base-url: https://api.openai.com/v1
+      api-key: demo
+      model-name: gpt-3.5-turbo
+      temperature: 0.0
+      timeout: PT60S
   in-memory:
     embedding-model:
       model-name: bge-small-zh