Use netCDF-c v4.9.3 #320

Job	Run time
rustfmt	1m 14s
Address sanitizer	1m 21s
mpi-runner	1m 26s
conda (ubuntu, conda-forge, stable)	57s
test apt (stable)	39s
test apt (beta)	41s
static builds (ubuntu-latest, stable)	1m 38s
test apt (nightly)	38s
static builds (windows-latest, stable-msvc)	4m 26s
conda (windows, conda-forge, stable)	2m 17s
static builds (windows-latest, stable-gnu)	5m 19s
conda (macos, conda-forge, stable)	1m 6s
static builds (macos-11, stable)	1s
static builds (macos-latest, stable)	1m 46s
	23m 29s

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