Port to actx.np.zeros #2382

Job	Run time
Mypy	2m 40s
Examples Conda Py3	6m 25s
Documentation	3m 25s
Tests for downstream project grudge	9m 44s
Pytest Firedrake	5m 58s
Tests for downstream project pytential	50m 9s
Examples Firedrake	3m 12s
Pylint	3m 8s
Tests for downstream project mirgecom	3s
Pytest Conda Py3	10m 30s
Tests for downstream project mirgecom_examples	4s
Ruff	11s
	1h 35m 29s

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