Add exception rules for new cops

FactoryBot/FactoryAssociationWithStrategy, exclude spec/factories/legal_aid_applications.rb
This is because there are too many traits that create objects that loop back

RSpec/IndexedLet, set the max number of spec variables to 2

This will allow up to 2 number let variables e.g.
```ruby
    let!(:transaction1) { create(:bank_transaction, :benefits, happened_at: 10.days.ago) }
    let!(:transaction2) { create(:bank_transaction, :benefits, happened_at: 40.days.ago) }
```
But trying to create `transaction3` will raise an error

The aim is to slowly reduce the number over time to 1 as we phase out the use of large numbered blocks

We also exclude spec/services/cfe/* as the CFE classic integration is due to be deleted soon

.rubocop.yml

@@ -26,3 +26,12 @@ Lint/AmbiguousBlockAssociation:
 Style/ZeroLengthPredicate:
   Exclude:
     - app/controllers/status_controller.rb
+
+FactoryBot/FactoryAssociationWithStrategy:
+  Exclude:
+    - spec/factories/legal_aid_applications.rb # Too many traits create objects that loop back
+
+RSpec/IndexedLet:
+  Max: 2
+  Exclude:
+    - spec/services/cfe/* # due to be deleted soon 🤞