PyAPI: fix memory leaks in dictionary assignment

Thanks to Kévin Dietrich for spotting driver leak,
checked other uses of PyDict_SetItem and found more.

source/blender/python/generic/py_capi_utils.c

@@ -748,6 +748,7 @@ void PyC_RunQuicky(const char *filepath, int n, ...)
 		
 		/* set the value so we can access it */
 		PyDict_SetItemString(py_dict, "values", values);
+		Py_DECREF(values);
 
 		py_result = PyRun_File(fp, filepath, Py_file_input, py_dict, py_dict);