fix: add state management for oai assistant #4270

Job	Run time
lint	1m 3s
mypy (./packages/autogen-core)	3m 36s
pyright (./packages/autogen-core)	59s
mypy (./packages/agbench)	58s
format	1m 2s
pyright (./packages/agbench)	1m 7s
mypy (./packages/autogen-ext)	3m 49s
test (./packages/autogen-core)	1m 16s
pyright (./packages/autogen-ext)	1m 8s
mypy (./packages/autogen-agentchat)	1m 23s
test (./packages/autogen-ext)	4m 17s
pyright (./packages/autogen-agentchat)	58s
mypy (./packages/magentic-one-cli)	1m 30s
test (./packages/autogen-agentchat)	1m 17s
pyright (./packages/magentic-one-cli)	1m 6s
check-proto-changes-python	1m 22s
docs (./packages/autogen-core)	1m 39s
markdown-code-lint	2m 34s
docs-example-check (./packages/autogen-core)	3m 22s
samples-code-check	1m 0s
codecov (./packages/autogen-core)	12s
codecov (./packages/autogen-ext)	11s
codecov (./packages/autogen-agentchat)	8s
	35m 57s

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