Release 3166

Trello card

https://trello.com/c/NOHbwt7v

Context

We're seeing issues with a few schools not able to receive requests.
This could be due to our removal of subjects: physics with maths and vocational health.

Changes proposed in this pull request

• Refactor secondary_subjects scope in Bookings::Subject model to include only non-hidden secondary subjects
• Remove safe navigation from bookings_subject in placement_date_option.rb