fix change_context usages (#41361)

Author: Liudmila Molkova

sdk/ai/azure-ai-agents/azure/ai/agents/telemetry/_ai_agents_instrumentor.py

@@ -1197,7 +1197,7 @@ def trace_handle_submit_tool_outputs(self, function, *args, **kwargs):
         if span is None:
             return function(*args, **kwargs)
 
-        with span.change_context(span.span_instance):
+        with span.change_context(span):
             try:
                 result = function(*args, **kwargs)
             except Exception as exc:
@@ -1215,7 +1215,7 @@ async def trace_handle_submit_tool_outputs_async(self, function, *args, **kwargs
         if span is None:
             return await function(*args, **kwargs)
 
-        with span.change_context(span.span_instance):
+        with span.change_context(span):
             try:
                 result = await function(*args, **kwargs)
             except Exception as exc:
@@ -1261,7 +1261,7 @@ def trace_create_stream(self, function, *args, **kwargs):
         if span is None:
             return function(*args, **kwargs)
 
-        with span.change_context(span.span_instance):
+        with span.change_context(span):
             try:
                 kwargs["event_handler"] = self.wrap_handler(event_handler, span)
                 result = function(*args, **kwargs)
@@ -1310,7 +1310,7 @@ async def trace_create_stream_async(self, function, *args, **kwargs):
 
         # TODO: how to keep span active in the current context without existing?
         # TODO: dummy span for none
-        with span.change_context(span.span_instance):
+        with span.change_context(span):
             try:
                 kwargs["event_handler"] = self.wrap_async_handler(event_handler, span)
                 result = await function(*args, **kwargs)