PartDesign: remove preview update on property changed (#26803)

This recompute seemed unnecessary, and caused slowdowns when opening the file and recomputing. This decreases the time necessary to both open and recompute files that use boolean operations, and should not change anything regarding preview computation when the dialog is open.

(cherry picked from commit c1b40e3dfc)

src/Mod/PartDesign/App/FeatureBoolean.cpp

@@ -209,10 +209,6 @@ void Boolean::onChanged(const App::Property* prop)
         touch();
     }
 
-    if (strcmp(prop->getName(), "Shape") == 0) {
-        updatePreviewShape();
-    }
-
     Feature::onChanged(prop);
 }