Revert "Rails 7 update" (#25667)

Gemfile

Gemfile.lock

app/lib/inline_renderer.rb

app/lib/rss/channel.rb

app/lib/rss/item.rb

app/models/announcement.rb

app/models/concerns/account_search.rb

app/models/concerns/status_safe_reblog_insert.rb

app/models/notification.rb

app/serializers/initial_state_serializer.rb

app/services/account_search_service.rb

app/services/batched_remove_status_service.rb

config/application.rb

config/environments/development.rb

config/environments/production.rb

config/environments/test.rb

config/initializers/assets.rb

config/initializers/filter_parameter_logging.rb

config/initializers/new_framework_defaults_7_0.rb

db/schema.rb