Fix a false positive for RSpec/ExampleWithoutDescription when specify with multi-line block and missing description

This PR fixes a false positive for `RSpec/ExampleWithoutDescription` when `specify` with multi-line block and missing description.
This is because `specify` is recommended when there is no description.

refs: https://rspec.rubystyle.guide/#it-and-specify

```ruby
specify do
  # ...
end
```

Author: ydah

CHANGELOG.md

@@ -16,6 +16,7 @@
 - Add new `RSpec/RepeatedSubjectCall` cop. ([@drcapulet])
 - Add configuration option `ResponseMethods` to `RSpec/Rails/HaveHttpStatus`. ([@ydah])
 - Fix a false negative for `RSpec/DescribedClass` when class with constant. ([@ydah])
+- Fix a false positive for `RSpec/ExampleWithoutDescription` when `specify` with multi-line block and missing description. ([@ydah])
 
 ## 2.26.1 (2024-01-05)