Use RuboCop RSpec 2.24

This commit uses RuboCop RSpec 2.24 and suppress the following new offense:

```console
$ bundle exec rubocop
Inspecting 163 files
(snip)

Offenses:

spec/rubocop/ast/rubocop_compatibility_spec.rb:1:1: C: RSpec/SpecFilePathFormat:
Spec path should end with rubocop/ast/rubo_cop_compatibility*_spec.rb.
# frozen_string_literal: true

spec/rubocop/ast/rubocop_compatibility_spec.rb:3:54: W: [Correctable] Lint/RedundantCopDisableDirective:
Unnecessary disabling of RSpec/FilePath.
RSpec.describe RuboCop::AST::RuboCopCompatibility do # rubocop:disable RSpec/FilePath
                                                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

163 files inspected, 2 offenses detected, 1 offense autocorrectable
```

https://github.com/rubocop/rubocop-rspec/releases/tag/v2.24.0

.rubocop.yml

@@ -120,5 +120,9 @@ RSpec/NestedGroups:
 RSpec/MultipleMemoizedHelpers:
   Enabled: false
 
+RSpec/SpecFilePathFormat:
+  CustomTransform:
+    RuboCopCompatibility: rubocop_compatibility
+
 RSpec/StubbedMock:
   Enabled: false

spec/rubocop/ast/rubocop_compatibility_spec.rb

@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-RSpec.describe RuboCop::AST::RuboCopCompatibility do # rubocop:disable RSpec/FilePath
+RSpec.describe RuboCop::AST::RuboCopCompatibility do
   subject(:callback) { RuboCop::AST.rubocop_loaded }
 
   before do