Open page callback found, please add a comment before the line why there is no access restriction

     no_cache: 'TRUE'
   requirements:
+   # Please add comment manually here.
     _access: 'TRUE'

The report clearly states: Please add a comment before the line [explaining] why there is no access restriction. Please add comment manually here. does not explain whey there is not access restriction: It just a workaround to avoid phpcs complains.
At this point, it would be better to ignore the report, which is given for a test module.

@apaderno I have revised #2 and I have covered the points mentioned above

Please review, moving the issue to "needs review".

Should be done as a merge request, space missing after ,