Preprocessor: remove unused steady_state_growth option to pac_model

preprocessor @ eb006eca

-Subproject commit d1acee0631122da3dc90e1f81774389d6fa978a2
+Subproject commit eb006ecaeb6af84f445d2956853c4c89a92d7bc3

tests/pac/trend-component-1-mce/example_det.mod

@@ -30,7 +30,7 @@ gamma =  .7;
 
 trend_component_model(model_name=toto, eqtags=['eq:x1', 'eq:x2', 'eq:x1bar', 'eq:x2bar'], targets=['eq:x1bar', 'eq:x2bar']);
 
-pac_model(discount=beta, model_name=pacman, steady_state_growth=.0);
+pac_model(discount=beta, model_name=pacman);
 
 model;
 

tests/pac/trend-component-2-mce/example_sto.mod

@@ -30,7 +30,7 @@ gamma =  .7;
 
 trend_component_model(model_name=toto, eqtags=['eq:x1', 'eq:x2', 'eq:x1bar', 'eq:x2bar'], targets=['eq:x1bar', 'eq:x2bar']);
 
-pac_model(discount=beta, model_name=pacman, steady_state_growth=.0);
+pac_model(discount=beta, model_name=pacman);
 
 model(linear);