Remove `netcdf_engine` from Field and FieldSet #690

Job	Run time
py3.13 \| macos \| unit tests	7m 52s
mypy	3m 30s
py3.13 \| macos \| integration tests	13m 35s
py3.13 \| ubuntu \| unit tests	9m 58s
py3.13 \| ubuntu \| integration tests	14m 5s
py3.13 \| windows \| unit tests	10m 42s
py3.13 \| windows \| integration tests	26m 49s
py3.10 \| ubuntu \| unit tests	10m 50s
py3.10 \| ubuntu \| integration tests	13m 47s
py3.11 \| ubuntu \| unit tests	10m 27s
py3.12 \| ubuntu \| unit tests	10m 32s
merge-test-artifacts	0s
	2h 12m 7s

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