MONGOID-5656 - Fix broken FLE spec in mongoid/tasks/database_rake_spec

[johnnyshields]

I am pretty sure this spec related to FLE is broken and Mongoid is skipping it in test runs.

This PR does not fix the missed spec run (I will raise a separate PR which adds it into Github actions), but does fix the spec itself.

You can see the failure here: https://github.com/tablecheck/mongoid-ultra/actions/runs/5989956616/job/16246745994

There are two problems:

1. The DB client for encrypted is not configured correctly.
2. OptionParser#order! is choking on RSpec's default --pattern option. This might be somewhat environment specific, but AFAIK RSpec injects this automatically.

[johnnyshields]

@jamis @comandeo can you try running rspec spec/mongoid/tasks/database_rake_spec.rb with FLE options enabled locally? It appears to be breaking because it can't find the db client named encrypted. It appears that specs even like db:setup and db:test:prepare break when using FLE because they are trying to create indexes some model which uses client encrypted.

(Note the specs will succeed if you don't have FLE enabled.)

I think I'm out of my depth on this one.