compiler: Intify StencilDimension attributes

[FabioLuporini]

Test in PRO as you need to work hard with substitutions to trigger the following error inside sympy

/venv/lib/python3.10/site-packages/sympy/core/basic.py:413: in compare
    c = l.compare(r)
/venv/lib/python3.10/site-packages/sympy/core/basic.py:419: in compare
    c = (l > r) - (l < r)
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

self = True, other = False

    def _noop(self, other=None):
>       raise TypeError('BooleanAtom not allowed in this context.')
E       TypeError: BooleanAtom not allowed in this context.

This is nothing relevant -- just a stupid exception when sympy needs to establish if A should precede B (or the other way round) in the arguments list of a given expression (in this case, of IndexDerivatives)

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 83.05%. Comparing base (a04b3af) to head (bc70ce4).
⚠️ Report is 2 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2755   +/-   ##
=======================================
  Coverage   83.04%   83.05%           
=======================================
  Files         248      248           
  Lines       50438    50438           
  Branches     4437     4437           
=======================================
+ Hits        41886    41890    +4     
+ Misses       7792     7789    -3     
+ Partials      760      759    -1     

Flag	Coverage Δ
pytest-gpu-aomp-amdgpuX	68.76% <100.00%> (+0.01%)	⬆️
pytest-gpu-nvc-nvidiaX	69.29% <100.00%> (+0.01%)	⬆️

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