Fix bug in `index` api #4555

Job	Run time
Python 3.8 extended tests	5m 4s
Python 3.9 extended tests	4m 9s
Python 3.10 extended tests	4m 29s
Python 3.11 extended tests	4m 29s
lint / build (3.8)	1m 49s
pydantic-compatibility / Pydantic v1/v2 compatibility - Python 3.8	1m 46s
lint / build (3.11)	1m 48s
pydantic-compatibility / Pydantic v1/v2 compatibility - Python 3.9	1m 36s
pydantic-compatibility / Pydantic v1/v2 compatibility - Python 3.10	1m 27s
test / Python 3.8	1m 27s
pydantic-compatibility / Pydantic v1/v2 compatibility - Python 3.11	1m 31s
test / Python 3.9	1m 47s
test / Python 3.10	1m 28s
test / Python 3.11	1m 39s
	34m 29s

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