Update README.md python example #2272

Job	Run time
format	51s
mypy (./packages/autogen-core)	2m 11s
mypy (./packages/autogen-magentic-one)	1m 13s
check-proto-changes-python	1m 21s
mypy (./packages/agbench)	53s
docs-example-check (./packages/autogen-core)	2m 19s
mypy (./packages/autogen-ext)	1m 47s
docs (./packages/autogen-core)	1m 22s
mypy (./packages/autogen-agentchat)	1m 7s
lint	52s
pyright (./packages/autogen-core)	1m 11s
test (./packages/autogen-core)	55s
pyright (./packages/autogen-magentic-one)	1m 20s
test (./packages/autogen-magentic-one)	1m 45s
pyright (./packages/agbench)	1m 2s
test (./packages/autogen-ext)	2m 21s
pyright (./packages/autogen-ext)	57s
test (./packages/autogen-agentchat)	1m 6s
pyright (./packages/autogen-agentchat)	56s
	25m 29s

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