BUG: Decoupled config files should not depend

The ITK*snake_case.py and the ITK*Config.py files
should not be dependant on each other during
the build process.  Previous attempt to decouple
the process resulted in accidently leaving
overly perscriptive checking, and unnecessary
file creation dependancy order that is not
required.

Wrapping/Generators/SwigInterface/igenerator.py

@@ -1242,21 +1242,13 @@ def generate_swig_input(moduleName):
         generate_swig_input(moduleName)
 
     snake_case_file = options.snake_case_file
-    main_config_file = snake_case_file.replace("_snake_case.py","Config.py")
-    if not os.path.exists(main_config_file):
-        print(
-            f"ERROR: required {main_config_file} file does not exist\n"
-            f"can not append to {snake_case_file}\n"
+    with open(snake_case_file, "w") as ff:
+        ff.write("snake_case_functions = (")
+        # Ensure that the functions are sorted alphabetically to ensure consistency
+        # in the generated file structure.
+        sorted_snake_case_process_object_functions = sorted(
+            snake_case_process_object_functions
         )
-        sys.exit(-1)
-    else:
-        with open(snake_case_file, "w") as ff:
-            ff.write("snake_case_functions = (")
-            # Ensure that the functions are sorted alphabetically to ensure consistency
-            # in the generated file structure.
-            sorted_snake_case_process_object_functions = sorted(
-                snake_case_process_object_functions
-            )
-            for function in sorted_snake_case_process_object_functions:
-                ff.write("'" + function + "', ")
-            ff.write(")\n")
+        for function in sorted_snake_case_process_object_functions:
+            ff.write("'" + function + "', ")
+        ff.write(")\n")