Update Custom Indexes section in api.rst #18028

Job	Run time
Event File	4s
detect ci trigger	6s
ubuntu-latest py3.11	9m 37s
macos-latest py3.13	7m 45s
windows-latest py3.13	15m 52s
ubuntu-latest py3.13	10m 0s
ubuntu-latest py3.11 bare-minimum	1m 45s
ubuntu-latest py3.13 flaky	1m 24s
macos-latest py3.11	6m 3s
ubuntu-latest py3.11 bare-min-and-scipy	1m 57s
ubuntu-latest py3.13 all-but-numba	8m 31s
ubuntu-latest py3.11 min-all-deps	9m 26s
windows-latest py3.11	16m 48s
ubuntu-latest py3.12 all-but-dask	6m 10s
ubuntu-latest py3.13 mypy	3m 17s
ubuntu-latest py3.11 mypy	3m 10s
	1h 41m 55s

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