Can we remove the space from InterpolationsRegridder?

[charleskawczynski]

I'm seeing huge stack traces in https://buildkite.com/clima/climaland-long-runs/builds/1330#01925384-a92c-4f92-885e-69fe03731fc1. I think it's because there are a lot (~23) of InterpolationsRegridder objects (and therefore spaces) in a DataLayouts kernel, and this results in a massive method signature

[Sbozzolo]

Yes, I think that should be possible. The only place where it is not easy is where we determine the extrapolation boundary conditions automatically (at the constructor):

ClimaUtilities.jl/ext/InterpolationsRegridderExt.jl

Lines 32 to 73 in 5171f8c

	"""
	InterpolationsRegridder(target_space::ClimaCore.Spaces.AbstractSpace
	[; extrapolation_bc::Tuple])
	An online regridder that uses Interpolations.jl
	Currently, InterpolationsRegridder is only implemented for LatLong and LatLongZ spaces. It
	performs linear interpolation along each of the directions (separately). By default, it
	imposes periodic boundary conditions for longitude, flat for latitude, and throwing errors
	when extrapolating in z. This can be customized by passing the `extrapolation_bc` keyword
	argument.
	InterpolationsRegridder is GPU and MPI compatible in the simplest possible way: each MPI
	process has the entire input data and everything is copied to GPU.
	Keyword arguments
	=================
	The optional keyword argument `extrapolation_bc` controls what should be done when the
	interpolation point is not in the domain of definition. This has to be a tuple of N
	elements, where N is the number of spatial dimensions. For 3D spaces, the default is
	`(Interpolations.Periodic(), Interpolations.Flat(), Interpolations.Throw())`.
	"""
	function Regridders.InterpolationsRegridder(
	target_space::ClimaCore.Spaces.AbstractSpace;
	extrapolation_bc::Union{Nothing, Tuple} = nothing,
	)
	coordinates = ClimaCore.Fields.coordinate_field(target_space)
	if isnothing(extrapolation_bc)
	extrapolation_bc = ()
	if eltype(coordinates) <: ClimaCore.Geometry.LatLongPoint
	extrapolation_bc = (Intp.Periodic(), Intp.Flat())
	elseif eltype(coordinates) <: ClimaCore.Geometry.LatLongZPoint
	extrapolation_bc = (Intp.Periodic(), Intp.Flat(), Intp.Throw())
	else
	error("Only lat-long, lat-long-z spaces are supported")
	end
	end
	return InterpolationsRegridder(target_space, coordinates, extrapolation_bc)
	end

This would change a little bit the spirit of the regridder (the initial idea was to have a regridder attached to a specific variable and calling it multitple times would be cheap), but I don't see big problems with this.