f - [bugfix] [ModelicaSystemABC] fix _prepare_input_data() - ensure returned data is dict[str, str]

Author: syntron

OMPython/modelica_system_abc.py

@@ -795,7 +795,7 @@ def prepare_str(str_in: str) -> dict[str, str]:
                     input_data = input_data | prepare_str(item)
             elif isinstance(input_arg, dict):
                 input_arg_str: dict[str, str] = {}
-                for key, val in input_arg:
+                for key, val in input_arg.items():
                     if not isinstance(key, str) or len(key) == 0:
                         raise ModelicaSystemError(f"Invalid key for set*() functions: {repr(key)}")
                     input_arg_str[key] = str(val)