Use Adapter.const_get instead of safe_constantize

(Thanks to sandstrom for the reference to ActiveJob::QueueAdapters
https://github.com/rails/rails/blob/a11571cec3213753d63ac3e6b4bb3b97fe2594a6/activejob/lib/active_job/queue_adapters.rb#L123-L133

Author: bf4

lib/active_model/serializer/adapter.rb

@@ -60,11 +60,7 @@ def lookup(adapter)
             register(adapter_name, adapter_class)
             adapter_class
           }
-        rescue ArgumentError
-          failure_message =
-            "Unknown adapter: #{adapter.inspect}. Valid adapters are: #{adapters}"
-          raise UnknownAdapterError, failure_message, $!.backtrace
-        rescue NameError
+        rescue NameError, ArgumentError
           failure_message =
             "NameError: #{$!.message}. Unknown adapter: #{adapter.inspect}. Valid adapters are: #{adapters}"
           raise UnknownAdapterError, failure_message, $!.backtrace
@@ -73,7 +69,7 @@ def lookup(adapter)
         # @api private
         def find_by_name(adapter_name)
           adapter_name = adapter_name.to_s.classify.tr('API', 'Api')
-          "ActiveModel::Serializer::Adapter::#{adapter_name}".safe_constantize or # rubocop:disable Style/AndOr
+          ActiveModel::Serializer::Adapter.const_get(adapter_name.to_sym) or # rubocop:disable Style/AndOr
             fail UnknownAdapterError
         end
         private :find_by_name