fix: moved migration into old migration instead of new one

Author: raphael-goetz

db/migrate/20260531180000_create_execution_results.rb

@@ -11,7 +11,7 @@ def change
       t.jsonb :success
       t.jsonb :error
 
-      t.check_constraint 'num_nonnulls(success, error) = 1',
+      t.check_constraint 'num_nonnulls(success, error) <= 1',
                          name: check_constraint_name(:execution_results, :result, :at_most_one)
 
       t.index '"flow_id", LOWER("execution_identifier")',
@@ -33,7 +33,7 @@ def change
       t.jsonb :success
       t.jsonb :error
 
-      t.check_constraint 'num_nonnulls(success, error) = 1',
+      t.check_constraint 'num_nonnulls(success, error) <= 1',
                          name: check_constraint_name(:execution_node_results, :result, :at_most_one)
 
       t.index %i[execution_result_id position],
@@ -49,7 +49,7 @@ def change
                    foreign_key: { on_delete: :cascade },
                    index: false
       t.integer :position, null: false
-      t.jsonb :value, null: false
+      t.jsonb :value
 
       t.index %i[execution_node_result_id position],
               unique: true,