switch back to require_nested due to linux load error

[jameswnl]

Seems linux is having problem with this change in loading order. Revert these calls for now

@miq-bot add_labels bug

Reported issue on linux:

TypeError: superclass must be a Class (Module given)
app/models/manageiq/providers/embedded_ansible/automation_manager/cloud_credential.rb:2:in `<top (required)>'
app/models/manageiq/providers/embedded_ansible/automation_manager/amazon_credential.rb:1:in `<top (required)>'
lib/extensions/require_nested.rb:11:in `require_nested'
lib/extensions/require_nested.rb:23:in `block in require_nested_all'
lib/extensions/require_nested.rb:21:in `each'
lib/extensions/require_nested.rb:21:in `require_nested_all'
app/models/manageiq/providers/embedded_ansible/automation_manager.rb:3:in `<class:AutomationManager>'
app/models/manageiq/providers/embedded_ansible/automation_manager.rb:1:in `<top (required)>'
lib/extensions/descendant_loader.rb:235:in `load_subclasses'
lib/extensions/descendant_loader.rb:255:in `descendants'
app/models/blacklisted_event.rb:26:in `seed'
lib/evm_database.rb:80:in `block (2 levels) in seed'
lib/evm_database.rb:69:in `each'
lib/evm_database.rb:69:in `block in seed'
lib/extensions/ar_table_lock.rb:21:in `block (2 levels) in with_lock'
lib/extensions/ar_table_lock.rb:21:in `block in with_lock'
lib/extensions/ar_table_lock.rb:15:in `with_lock'
lib/evm_database.rb:68:in `seed'
db/seeds.rb:8:in `<top (required)>'
bin/rails:4:in `require'
bin/rails:4:in `<main>'
Tasks: TOP => db:seed
(See full trace by running task with --trace)

[miq-bot]

Checked commit jameswnl@5d77b2d with ruby 2.3.3, rubocop 0.52.1, haml-lint 0.20.0, and yamllint 1.10.0
2 files checked, 0 offenses detected
Everything looks fine. 🍪

[jrafanie]

This was a partial revert of #17793