Remove adaptor docs rag

[hanna-paasivirta]

Short Description

Removes adaptor documentation embedding similarity search, as this returns many irrelevant docs and we have already added key information about relevant adaptors to the prompt.

• Removed adaptor_docs as a RAG search option, so that queries now only search general OpenFn platform docs
• Updated search_docs_system_prompt examples to reflect general docs (not adaptor-specific)
• Updated job_chat system prompt to clarify these are general docs only and may not be relevant to the user's adaptor/situation
• Updates tests accordingly to remove the doc_type assertion from test_generate_queries_returns_valid_structure

Fixes #396

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[josephjclark]

@hanna-paasivirta is everything commited to this branch? I can't see any functional change between some wording in prompts 🤔

[hanna-paasivirta]

@josephjclark Sorry you're right – I just removed the docs type filter when I should have specified the docs type to narrow it down. I've added a test as well to verify it only searches general docs.