Fix Style/SlicingWithRange cop (#25923)

.rubocop_todo.yml

@@ -908,21 +908,6 @@ Style/SingleArgumentDig:
   Exclude:
     - 'lib/webpacker/manifest_extensions.rb'
 
-# This cop supports unsafe autocorrection (--autocorrect-all).
-Style/SlicingWithRange:
-  Exclude:
-    - 'app/lib/emoji_formatter.rb'
-    - 'app/lib/text_formatter.rb'
-    - 'app/models/account_alias.rb'
-    - 'app/models/domain_block.rb'
-    - 'app/models/email_domain_block.rb'
-    - 'app/models/preview_card_provider.rb'
-    - 'app/validators/status_length_validator.rb'
-    - 'db/migrate/20190726175042_add_case_insensitive_index_to_tags.rb'
-    - 'lib/active_record/batches.rb'
-    - 'lib/mastodon/premailer_webpack_strategy.rb'
-    - 'lib/tasks/repo.rake'
-
 # This cop supports safe autocorrection (--autocorrect).
 # Configuration parameters: EnforcedStyle.
 # SupportedStyles: require_parentheses, require_no_parentheses