Python: [BREAKING] Remove deprecated Python OpenAI/Azure AI surfaces (#4990)

* [BREAKING] Remove deprecated Python OpenAI/Azure AI surfaces

Also clean up follow-on docs, environment guidance, package metadata, and lab test stability.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Fix deleted semantic-kernel sample links

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Address PR review feedback

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* improve foundry language

* Fix A2A Foundry sample regression

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

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Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

python/samples/02-agents/tools/function_tool_with_kwargs.py

@@ -4,7 +4,7 @@ import asyncio
 from typing import Annotated
 
 from agent_framework import Agent, FunctionInvocationContext, tool
-from agent_framework.openai import OpenAIResponsesClient
+from agent_framework.openai import OpenAIChatClient
 from dotenv import load_dotenv
 from pydantic import Field
 
@@ -44,7 +44,7 @@ def get_weather(
 
 async def main() -> None:
     agent = Agent(
-        client=OpenAIResponsesClient(),
+        client=OpenAIChatClient(),
         name="WeatherAgent",
         instructions="You are a helpful weather assistant.",
         tools=[get_weather],