Remove `netcdf_engine` from Field and FieldSet #693

Job	Run time
py3.13 \| macos \| integration tests	12m 22s
py3.13 \| macos \| unit tests	9m 21s
mypy	3m 23s
py3.13 \| ubuntu \| integration tests	14m 0s
py3.13 \| ubuntu \| unit tests	9m 53s
py3.13 \| windows \| integration tests	22m 27s
py3.13 \| windows \| unit tests	12m 59s
py3.10 \| ubuntu \| integration tests	13m 10s
py3.10 \| ubuntu \| unit tests	10m 56s
py3.11 \| ubuntu \| unit tests	10m 15s
py3.12 \| ubuntu \| unit tests	10m 17s
merge-test-artifacts	0s
	2h 9m 3s

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