Add ghosting to pass the boundary test for block material

Ideally, we would use a postprocessor that currently does not have an issue with insufficient
ghosting when used on its own, see idaholab#19534. But I dont think there is one that will trigger
the ghosting we want. I could admittedly make a new one, which would be a rework of SideAverageMaterialProperty,
but it could make that one confusing.

test/tests/materials/piecewise_by_block_material/test.i

@@ -21,6 +21,21 @@
   []
 []
 
+[Variables]
+  [dummy]
+    type = MooseVariableFVReal
+  []
+[]
+
+# This is added to have sufficient ghosting layers, see #19534
+[FVKernels]
+  [diff]
+    type = FVDiffusion
+    variable = 'dummy'
+    coeff = 1
+  []
+[]
+
 [AuxVariables]
   [u]
     type = MooseVariableFVReal
@@ -80,4 +95,9 @@
 
 [Outputs]
   exodus = true
+  # To get level of ghosting
+  [console]
+    type = Console
+    system_info = 'framework mesh aux nonlinear execution relationship'
+  []
 []

test/tests/materials/piecewise_by_block_material/tests

@@ -6,6 +6,7 @@
     exodiff = test_out.e
     requirement = 'The system shall provide a material object that can, for a single material property, map subdomain IDs to a possibly discontinuous property value.'
     design = 'PiecewiseConstantByBlockMaterial.md'
+    ad_indexing_type = 'global'
   []
   [functor]
     type = Exodiff