Pin sidekiq-unique-jobs to version 8.0.7 or earlier

A [bug in version
8.0.8](mhenrixon/sidekiq-unique-jobs#846)
means jobs never get processed when using `until_and_while_executing`
lock type.

Therefore pinning to use an earlier version that does not have this
issue.

Gemfile

@@ -20,7 +20,7 @@ gem "plek"
 gem "rack_strip_client_ip"
 gem "rails-controller-testing"
 gem "sentry-sidekiq"
-gem "sidekiq-unique-jobs"
+gem "sidekiq-unique-jobs", "< 8.0.8"
 gem "sprockets-rails"
 gem "state_machines-mongoid"
 

Gemfile.lock

@@ -781,7 +781,7 @@ DEPENDENCIES
   rspec-sidekiq
   rubocop-govuk
   sentry-sidekiq
-  sidekiq-unique-jobs
+  sidekiq-unique-jobs (< 8.0.8)
   simplecov
   sprockets-rails
   state_machines-mongoid