Python: Bug: Azure AI Search samples missing required source_id parameter #3945

Description

The Azure AI Search sample files don't pass the required source_id positional argument to AzureAISearchContextProvider.__init__(), causing a TypeError at runtime.

Steps to reproduce

Run either of the sample files:

• python/samples/02-agents/context_providers/azure_ai_search/azure_ai_with_search_context_agentic.py
• python/samples/02-agents/context_providers/azure_ai_search/azure_ai_with_search_context_semantic.py

Error

TypeError: AzureAISearchContextProvider.__init__() missing 1 required positional argument: 'source_id'

Root cause

AzureAISearchContextProvider inherits from BaseContextProvider, which requires source_id as the first positional argument.

The constructor signature is:

def __init__(self, source_id: str, endpoint: str | None = None, ...)

But the samples construct it without source_id:

search_provider = AzureAISearchContextProvider(
    endpoint=search_endpoint,
    ...
)

Fix

Either:

1. Add source_id to the sample calls, e.g. AzureAISearchContextProvider(source_id="azure-ai-search", endpoint=..., ...)
2. Or give source_id a default value in AzureAISearchContextProvider.__init__() (e.g. source_id: str = "azure-ai-search")

Option 2 would be more user-friendly since the other built-in providers don't require callers to invent an ID.