nabla2_...damping refactoring and some stencil tests' xfails cleanup

[nfarabullini]

refactoring of init_nabla2_factor_in_upper_damping_zone to a gt4py stencil

removal of:

        if isinstance(grid, IconGrid) and grid.limited_area:
            pytest.xfail(
                "Execution domain needs to be restricted or boundary taken into account in stencil."
            )

and consequent changes

[halungge]

Generally, for the tests why don't you use the Output class from test_utils.helpers to restrict the comparison domain? I think that was introduced exactly for that.

In the diffusion: mostly revise the field allocations that you do.

[nfarabullini]

cscs-ci run default

[github-actions]

Mandatory Tests

Please make sure you run these tests via comment before you merge!

• cscs-ci run default
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In case your change might affect downstream icon-exclaim, please consider running

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For more detailed information please look at CI in the EXCLAIM universe.

[nfarabullini]

launch jenkins spack

[halungge]

LGTM