Remove `netcdf_engine` from Field and FieldSet #688

Job	Run time
py3.13 \| macos \| integration tests	12m 21s
mypy	3m 30s
py3.13 \| ubuntu \| integration tests	14m 49s
py3.13 \| macos \| unit tests	7m 49s
py3.13 \| windows \| integration tests	14m 49s
py3.13 \| ubuntu \| unit tests	10m 4s
py3.10 \| ubuntu \| integration tests	14m 45s
py3.13 \| windows \| unit tests	12m 51s
py3.10 \| ubuntu \| unit tests	10m 55s
py3.11 \| ubuntu \| unit tests	10m 36s
py3.12 \| ubuntu \| unit tests	10m 45s
merge-test-artifacts	1s
	2h 3m 15s

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