Removing the Groups from the Accounts>Groups page doesn't remove the references from the Project Permissions page

Issue Summary

Removing the Groups from the Accounts>Groups page doesn't remove the references from the Project Permissions page and the Global permissions page

Steps to Reproduce

1. Create a New group named "new_test_group"
2. Add a user to the Group
3. Add the Group Access for "new_test_group" under the Global permissions page.
4. Add the Group to the Project Permissions the users from the group are able to access the Project as expected
5. Remove the "new_test_group" Group from the Accounts> Groups page
6. The users are no longer able to access the Project as expected however the "new_test_group" is still listed on the Project Permissions page which should have been removed
   
7. When clicked on the "new_test_group" it throws an error as group does not exist.
   

Expected Results

When the Group is deleted from the Accounts>Groups page the same should be removed from the Global permissions page and Project Permissions page

Actual Results

The deleted group is still listed in the Global permissions page and Project Permissions page

Workaround

The deleted group which are still being listed the Global permissions page and Project Permissions page must be removed manually.