Move rspec-sidekiq to test group

This gem is being installed in the `development` environment, meaning it
runs when using the application locally, meaning jobs don't actually get
enqueued.

Moving it to be `test` only, since that is the only time it is actually
needed.

Gemfile

@@ -33,7 +33,6 @@ group :development, :test do
   gem "pact", require: false
   gem "pact_broker-client", require: false
   gem "rspec-rails"
-  gem "rspec-sidekiq"
   gem "rubocop-govuk"
   gem "simplecov"
   gem "webmock", require: false
@@ -42,3 +41,7 @@ end
 group :development do
   gem "listen"
 end
+
+gem "test" do
+  gem "rspec-sidekiq"
+end

Gemfile.lock

@@ -627,11 +627,6 @@ GEM
       rspec-expectations (~> 3.13)
       rspec-mocks (~> 3.13)
       rspec-support (~> 3.13)
-    rspec-sidekiq (5.0.0)
-      rspec-core (~> 3.0)
-      rspec-expectations (~> 3.0)
-      rspec-mocks (~> 3.0)
-      sidekiq (>= 5, < 8)
     rspec-support (3.13.1)
     rubocop (1.64.1)
       json (~> 2.3)
@@ -668,6 +663,7 @@ GEM
     ruby-vips (2.2.1)
       ffi (~> 1.12)
     ruby2_keywords (0.0.5)
+    rubytest (0.8.1)
     securerandom (0.3.1)
     sentry-rails (5.19.0)
       railties (>= 5.0)
@@ -719,6 +715,8 @@ GEM
     table_print (1.5.7)
     term-ansicolor (1.11.2)
       tins (~> 1.0)
+    test (1.0.0)
+      rubytest
     thor (1.3.2)
     timeout (0.4.1)
     tins (1.33.0)
@@ -778,13 +776,13 @@ DEPENDENCIES
   rails (= 7.2.1)
   rails-controller-testing
   rspec-rails
-  rspec-sidekiq
   rubocop-govuk
   sentry-sidekiq
   sidekiq-unique-jobs
   simplecov
   sprockets-rails
   state_machines-mongoid
+  test
   webmock
 
 BUNDLED WITH