Remove already removed AggregateFailuresByDefault from default.yml

`AggregateFailuresByDefault` option of `MultipleExpectations` has been
removed in #760.

Author: yujideveloper

config/default.yml

@@ -324,7 +324,6 @@ RSpec/MultipleExpectations:
   Description: Checks if examples contain too many `expect` calls.
   Enabled: true
   Max: 1
-  AggregateFailuresByDefault: false
   StyleGuide: https://www.rubydoc.info/gems/rubocop-rspec/RuboCop/Cop/RSpec/MultipleExpectations
 
 RSpec/MultipleSubjects:

manual/cops_rspec.md

@@ -2058,7 +2058,6 @@ end
 Name | Default value | Configurable values
 --- | --- | ---
 Max | `1` | Integer
-AggregateFailuresByDefault | `false` | Boolean
 
 ### References