ML/LLM: Optimize LangChain installation extras (#497)

LangChain does not provide `extra` labels for community dependencies
any longer.

Author: amotl

topic/machine-learning/llm-langchain/requirements.txt

@@ -17,6 +17,6 @@ unstructured<0.15
 
 # Development.
 # cratedb-toolkit @ git+https://github.com/crate-workbench/cratedb-toolkit.git@main
-langchain[cratedb,openai] @ git+https://github.com/crate-workbench/langchain.git@cratedb#subdirectory=libs/langchain
+langchain @ git+https://github.com/crate-workbench/langchain.git@cratedb#subdirectory=libs/langchain
 langchain-community @ git+https://github.com/crate-workbench/langchain.git@cratedb#subdirectory=libs/community
 # pueblo[cli,fileio,nlp] @ git+https://github.com/pyveci/pueblo.git@main