Remove `netcdf_engine` from Field and FieldSet #699

Job	Run time
mypy	3m 18s
py3.13 \| macos \| unit tests	6m 19s
py3.13 \| macos \| integration tests	6m 16s
py3.13 \| ubuntu \| unit tests	6m 16s
py3.13 \| ubuntu \| integration tests	6m 15s
py3.13 \| windows \| unit tests	6m 7s
py3.13 \| windows \| integration tests	6m 10s
py3.10 \| ubuntu \| unit tests	6m 17s
py3.10 \| ubuntu \| integration tests	6m 15s
py3.11 \| ubuntu \| unit tests	6m 15s
py3.12 \| ubuntu \| unit tests	6m 15s
merge-test-artifacts	1s
	1h 5m 44s

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