Upgrade Sequel

- Serialized attributes have symbols for keys until they are reloaded from the db
- Page 0 no longer exists in paginated responses, it is always page 1 now.
- Fixed bug in preloaded_object_serializer where it would load to_one associations before checking them

[#73151346]

Signed-off-by: Zach Robinson <zrobinson@pivotallabs.com>
Remove savepoint: true from code and specs now that auto_savepoint works

[#73151346]

Signed-off-by: Eric Malm <emalm@pivotallabs.com>