Merge pull request #20230 from edx/feanil/remove_unused_files

Remove monitoring files.

requirements/monitoring/requirements.txt

-# This requirements.txt file is meant to pull in other requirements.txt files so that
-# dependency monitoring tools like gemnasium.com can easily process them.
-
-# These tools should be updated to use requirements/edx/development.txt
-# instead, as that is now a comprehensive collection of all dependencies
-# used to run, test, or develop LMS and Studio.  Then this file can be
-# safely deleted.
-
--r ../edx/development.txt

requirements/monitoring/sandbox-requirements.txt

-# This requirements.txt file is meant to pull in other requirements.txt files so that
-# dependency monitoring tools like gemnasium.com can easily process them.
-
-# These tools should be updated to use requirements/edx-sandbox/base.txt
-# instead, as that is now a comprehensive collection of all dependencies
-# installed in code sandboxes.  Then this file can be safely deleted.
-
--r ../edx-sandbox/base.txt