remove duplicated call to mpChildrenShapes->SelectionChanged()

Found when investigating performance bottlenecks of fdo#75486, after the
selection is completed ScTabViewObj::getSelection() is called multiple
times, each creating a ScCellRangesObj of the range list of filtered
ranges, which then is used for
ScChildrenShapes::FindSelectedShapesChanges()

The duplicated call was introduced with
b4133247
but IMHO does not make any sense at all unless it has obscure side
effects, it only slows down things even more.

Change-Id: I3cee2e3e62c24ad72efb8cc2021e74d0afc70b69

sc/source/ui/Accessibility/AccessibleDocument.cxx

@@ -1691,10 +1691,6 @@ void SAL_CALL ScAccessibleDocument::selectionChanged( const lang::EventObject& /
 
         CommitChange(aEvent);
     }
-    if(mpChildrenShapes )
-    {
-        mpChildrenShapes->SelectionChanged();
-    }
 }
 
     //=====  XInterface  =====================================================