Python: [BREAKING] changed AIFunction to FunctionTool and @ai_function to @tool (#3413)

* changed AIFunction to FunctionTool and @ai_function to @tool

* test and mypy fixes

* mypy fix

* switch function tool to always_require

* fix noop

* fix github copilot imports

* test fixes

* fix ollama test

* fixes for tests

* fix tests

* reverted change to always_require and extended timeout

* fix test

python/samples/getting_started/observability/advanced_zero_code.py

@@ -9,6 +9,7 @@ from agent_framework.openai import OpenAIResponsesClient
 from opentelemetry.trace import SpanKind
 from opentelemetry.trace.span import format_trace_id
 from pydantic import Field
+from agent_framework import tool
 
 if TYPE_CHECKING:
     from agent_framework import ChatClientProtocol
@@ -38,7 +39,8 @@ You can also set the environment variables instead of passing them as CLI argume
 
 """
 
-
+# NOTE: approval_mode="never_require" is for sample brevity. Use "always_require" in production; see samples/getting_started/tools/function_tool_with_approval.py and samples/getting_started/tools/function_tool_with_approval_and_threads.py.
+@tool(approval_mode="never_require")
 async def get_weather(
     location: Annotated[str, Field(description="The location to get the weather for.")],
 ) -> str: