Cannot restore synthetics monitors

[hs-cwedseltoft]

Attempting to restore a synthetics monitor gives the following error:

/datadog_backup/lib/datadog_backup/core.rb:109:in 'rescue in restore': Request failed with error ["400", {"errors"=>["Cannot directly update a Synthetics Monitor, use Synthetics API instead."]}]

Steps to reproduce:

1. Run bundle exec datadog_backup backup
2. Make a change to a synthetics monitor with "type": "synthetics alert". For example, add a new tag.
3. Run bundle exec datadog_backup restore and you will see the error.