Remove CellId::to_cell

[masterleinad]

Deprecated in #11365.

[marcfehling]

You also need to get rid of the explicit instantiations:

dealii/source/grid/cell_id.inst.in

Lines 18 to 27 in 685249d

	for (deal_II_dimension : DIMENSIONS; deal_II_space_dimension : SPACE_DIMENSIONS)
	{
	#if deal_II_dimension <= deal_II_space_dimension
	template Triangulation<deal_II_dimension,
	deal_II_space_dimension>::cell_iterator
	CellId::to_cell(
	const Triangulation<deal_II_dimension, deal_II_space_dimension> &tria)
	const;
	#endif
	}

[tjhei]

Looks good, thank you. Did you grep all tests?

[masterleinad]

Looks good, thank you. Did you grep all tests?

Yes.