deps: update ndarray requirement from 0.15 to 0.16 #592

Job	Run time
documentation	1m 15s
rustfmt	21s
test (msrv, ubuntu-20.04, 1.77.0)	1m 5s
clippy	1m 11s
test (stable, ubuntu-20.04, stable)	1m 9s
benchmarks	1m 57s
test (beta, ubuntu-20.04, beta)	1m 7s
Miri	2m 18s
test (nightly, ubuntu-20.04, nightly)	59s
Optional features (approx selected)	40s
test (macos, macos-latest, stable)	55s
Optional features (none selected)	30s
test (win-msvc, windows-2019, stable)	2m 12s
static SuiteSparse (stable, ubuntu-20.04, stable)	37s
test (win-gnu, windows-2019, stable)	2m 20s
static SuiteSparse (macos, macos-latest, stable)	45s
static SuiteSparse (win-msvc, windows-2019, stable)	1m 35s
static SuiteSparse (win-gnu, windows-2019, stable)	1m 50s
	22m 46s

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